Publicis Sapient Interview Preparation and Recruitment Process


About Publicis Sapient


* Publicis Sapient is a digital business transformation company that partners with organizations globally to help them create and sustain competitive advantage in an increasingly digital world.  Founded in 1990 as Sapient in Cambridge, Massachusetts, by Jerry Greenberg and J. Stuart Moore, the company initially specialized in IT consulting with a fixed-time, fixed-price approach.

Publicis Sapient Interview Preparation

* In 2015, Sapient was acquired by Publicis Groupe, a multinational advertising and public relations company, for $3.7 billion.

* This acquisition led to the formation of Publicis.Sapient, integrating Sapient's capabilities with other digital assets of Publicis Groupe. Subsequent mergers, including those with SapientNitro and Razorfish, culminated in 2019 with the consolidation of SapientRazorfish and Sapient Consulting into a single brand, Publicis Sapient, under the leadership of CEO Nigel Vaz.

* Publicis Sapient offers a range of services, including strategy and consulting, customer experience and design, technology and engineering, marketing platforms, data and artificial intelligence, and innovation and digital product management.

* The company serves various industries such as consumer products, energy and commodities, financial services, health, retail, telecommunications, media and technology, transportation and mobility, travel and hospitality, and the public sector.

* With over 20,000 employees as of 2019 and a presence in more than 50 offices worldwide, Publicis Sapient leverages its global reach to bring deep industry expertise to forward-thinking brands around the world.



Publicis Sapient Recruitment Process

 

The recruitment process for Publicis Sapient typically varies depending on the role, location, and experience level (fresher vs. experienced candidate), but it generally follows a structured, multi-stage approach designed to assess technical skills, problem-solving abilities, and cultural fit. Here’s an overview based on common practices for Publicis Sapient, particularly for software engineering or technology-related roles as of April 9, 2025.

For freshers, the process often starts with an online application through their careers portal (careers.publicissapient.com), where candidates submit their resumes and details. This is followed by an online assessment, which usually includes a mix of aptitude, logical reasoning, verbal ability, and technical questions (like coding or core computer science concepts). The test might be conducted on platforms like AMCAT or HireVue, lasting around 60-130 minutes, with adaptive sections where you can’t revisit previous answers.

* For technical roles, expect 1-2 coding problems (e.g., easy to medium difficulty, like array manipulation or string processing) alongside MCQs on topics like OOPS, data structures, or database fundamentals.

*
If you clear the online test, the next stage is typically a technical interview—often one or two rounds.


* For freshers, the focus is on foundational knowledge: think questions about programming languages (Java, Python, etc.), algorithms, time complexity, and projects listed on your resume. You might be asked to code live (e.g., on a shared screen) or explain a solution to a problem like "reverse a linked list" or "implement a stack with getMin()."

* For experienced candidates, this digs deeper into past projects, system design, and specific tech stacks (e.g., Spring Boot, microservices, or cloud platforms).

* Following the technical rounds, there’s usually a managerial or behavioral round, sometimes called a "culture fit" interview. Here, they assess alignment with Publicis Sapient’s values—think collaboration, innovation, and client focus. Expect situational questions like "What would you do if a project deadline is at risk?" or "How do you handle team disagreements?" For senior roles, this might blend into a discussion about leadership or client interaction.

* The final step is often an HR round, where they discuss compensation, role expectations, and logistics. This can take a week or two after the technical stages, though the entire process—from application to offer—averages 2-4 weeks, depending on the role’s urgency and candidate pool. For freshers, the timeline might stretch slightly longer due to batch hiring (e.g., campus drives), while experienced hires might see a faster turnaround, sometimes within 10-20 days.

A few tips : tailor your resume to highlight relevant skills (e.g., agile experience, digital transformation projects), practice coding fundamentals, and brush up on Publicis Sapient’s SPEED framework (Strategy, Product, Experience, Engineering, Data) to show you understand their approach. The process is competitive but known to be fair and structured—interviewers are often described as supportive, especially for early-career candidates.

 

Publicis Sapient Interview Questions :

1 .
What is a protocol? Give some examples.
A protocol is a set of rules and standards that govern how devices communicate with each other over a network. Protocols define the format and meaning of the messages that are exchanged between devices, as well as the rules for how these messages should be transmitted and received.

There are many different types of protocols, and they are used in a variety of contexts, including computer networking, internet communication, and electronic communication. Some examples of protocols include:

* TCP/IP : The Transmission Control Protocol/Internet Protocol (TCP/IP) is a set of protocols that are used to connect devices on the internet and to transmit data between them. TCP/IP defines the rules for how data is formatted and transmitted over the internet, and is the foundation of the internet as we know it today.

* HTTP : The Hypertext Transfer Protocol (HTTP) is a protocol that is used to transmit data over the web. HTTP defines the rules for how web browsers and web servers communicate with each other and exchange data and is the basis for the web as we know it today.

* SMTP : The Simple Mail Transfer Protocol (SMTP) is a protocol that is used to transmit email messages between servers. SMTP defines the rules for how email messages are formatted and transmitted, and is a critical component of the email infrastructure.

* FTP : The File Transfer Protocol (FTP) is a protocol that is used to transfer files between computers over a network. FTP defines the rules for how files are formatted and transmitted, and is a common way to transfer large files between devices.

Protocols are essential for enabling communication and data exchange between devices on a network. They define the rules and standards that devices must follow in order to communicate with each other, and are a critical component of many different types of systems and networks.
2 .
What is a router? How does it work?
A router is a networking device that is used to connect different networks and to forward data packets between them. A router operates at the network layer of the OSI model and is responsible for routing data packets between devices on different networks based on their destination addresses.

To understand how a router works, it is helpful to understand the following key concepts :

* Network layer : As mentioned above, the network layer is responsible for routing data between devices on different networks. A router operates at this layer and uses routing protocols to determine the best path for data packets to take between networks.

* Routing table : A routing table is a data structure that is used by a router to store information about the networks it is connected to, and the paths that data packets should take to reach these networks. A router updates its routing table based on the information it receives from other routers and devices on the network.

* Forwarding : When a router receives a data packet, it looks up the destination address of the packet in its routing table and determines the best path to forward the packet to its destination. The router then sends the packet to the next hop on this path, which may be another router or a final destination device.

A router is a critical component of a network that enables devices on different networks to communicate with each other and exchange data. It does this by routing data packets between networks based on their destination addresses, and by using routing protocols and routing tables to determine the best path for the packets to take.
3 .
What is a switch? How does it differ from a hub?
A switch is a networking device that is used to connect devices on a network and to forward data packets between them. A switch operates at the data link layer of the OSI model and is responsible for forwarding data packets between devices on the same network based on their destination addresses.

A hub is a networking device that is used to connect devices on a network and to forward data packets between them. Like a switch, a hub operates at the data link layer of the OSI model and is responsible for forwarding data packets between devices on the same network.

There are several key differences between a switch and a hub :

* Address forwarding : A switch forwards data packets based on the destination address of the packet, while a hub forwards data packets to all connected devices regardless of their destination addresses.

* Performance : A switch is generally faster than a hub, as it is able to forward data packets more efficiently by only sending them to the intended destination device. A hub, on the other hand, broadcasts data packets to all connected devices, which can lead to slower performance.

* Intelligence : A switch is generally more intelligent than a hub, as it is able to learn the addresses of connected devices and build a forwarding table to optimize data forwarding. A hub, on the other hand, simply broadcasts data packets to all connected devices.

* Cost : Switches are generally more expensive than hubs, as they offer more advanced features and higher performance.

while both switches and hubs are used to connect devices on a network and forward data packets between them, they differ in terms of their performance, intelligence, and cost. Switches are generally faster and more intelligent than hubs, but are also more expensive.
4 .
What is a network? How does it differ from a system?
In computer science, a network is a collection of interconnected computers and devices that can communicate with each other to exchange data and resources. Networks can be classified based on their size, scope, and purpose, and can be as small as a home network with a few devices, or as large as the internet, which connects billions of devices worldwide.

A system, on the other hand, is a collection of interconnected components that work together to achieve a common goal or purpose. A system can be as simple as a mechanical system with a few parts or as complex as a computer system with hardware, software, and data.

There are several key differences between a network and a system :

* Size : Networks are typically larger than systems, and can encompass multiple systems and devices.

* Scope :  Networks often have a wider scope than systems, and can connect devices and systems across geographical distances.

* Purpose : Networks are often used to exchange data and resources between devices and systems, while systems are designed to achieve a specific goal or purpose.

* Interconnections : Networks are typically characterized by the interconnections between devices and systems, while systems are characterized by the interactions between their components.

while networks and systems have some similarities, they are distinct concepts that play different roles in computer science. Networks are used to connect devices and systems, while systems are used to achieve specific goals or purposes.
5 .
Explain the OSI model and its layers?
The OSI (Open Systems Interconnection) model is a framework for understanding how different systems and devices communicate with each other over a network. The OSI model divides the process of communication into seven layers, each of which performs a specific function in the process of transmitting and receiving data.

The seven layers of the OSI model are :

Physical Layer : This layer is responsible for transmitting raw data over a physical medium, such as a cable or wireless connection. It defines the electrical, mechanical, and functional characteristics of the physical connection.

Data Link Layer : This layer is responsible for organizing the raw data into frames, and for providing error detection and correction for the data. It also defines how devices on the network can access the physical medium and transmit data.

Network Layer : This layer is responsible for routing data between devices on the network, and for providing logical addressing and routing services. It defines how data is routed between devices, and how devices can communicate with each other.

In addition to routing data between devices and providing logical addressing and routing services, the Network Layer is also responsible for encapsulating data into packets and ensuring that packets are delivered to their intended destination.

Encapsulation is the process of adding protocol headers and trailers to the data as it moves through the network. These headers and trailers contain information such as source and destination addresses, packet sequence numbers, and error-checking codes. The Network Layer uses this information to route packets through the network to their intended destination.

The Network Layer also provides services for managing network congestion and ensuring the reliable delivery of packets. For example, it may use congestion control algorithms to prevent network congestion and packet loss, and it may use error correction codes to detect and correct errors in packet transmissions.

Overall, the Network Layer plays a critical role in ensuring that data is transmitted reliably and efficiently across the network, and in enabling devices to communicate with each other using logical addressing and routing services.

* Transport Layer : This layer is responsible for providing end-to-end transmission of data, and for ensuring that data is delivered reliably and efficiently. It also provides flow control and error recovery services.

* Session Layer : This layer is responsible for establishing, maintaining, and terminating communication sessions between devices. It also provides synchronization and checkpointing services to ensure data integrity.

* Presentation Layer : This layer is responsible for translating and formatting data in a way that is appropriate for the receiving device. It also provides encryption and compression services to protect data privacy and optimize transmission.

* Application Layer : This layer is responsible for providing services to user applications and for defining how applications can access the network. It provides the interface between the network and the application and defines how applications can send and receive data.

OSI model provides a standardized way of understanding how different systems and devices communicate with each other over a network and helps to ensure that different systems and devices can interoperate with each other. It is a widely-used and influential model in computer networking.
6 .
Define Null pointer and where can we use it?
In reference to the computer memory, a Null pointer is a pointer which points to an empty location. Or Null pointer is a pointer which points to nothing.

Following are the primary uses of the NULL pointer in C language :

* We mostly use a Null pointer to show the end of memory search.

* We can pass a NULL pointer as a function argument when we don?t want to pass a valid memory address.
7 .
What is static and dynamic binding?
Binding is a process of associating a method call with method definition.

The Binding in Java is of two types :

* Static Binding
* Dynamic Binding

Static Binding : If the type of object can be determined at compile-time by compiler then it is known as static binding.

Dynamic Binding : If the type of object can be determined at runtime by compiler then it is called as dynamic binding.
8 .
What are the various types of Polymorphism?
Polymorphism in Java is of two types :

* Static polymorphism
* Dynamic polymorphism

* Static Polymorphism : Static polymorphism is also termed as compile-time polymorphism because static polymorphism can be resolved at compile time. We can achieve static polymorphism through method overloading. Which means in a class there are more than one method which has the same name but different parameter, or return type or the number of parameters.

* Dynamic Polymorphism : Dynamic polymorphism is also known as dynamic method dispatch or runtime polymorphism. Dynamic polymorphism is a process in which call to an overridden method can be resolved at runtime instead of compile time, hence it is also known as late binding. In dynamic polymorphism, an overridden method is called through the reference variable of the superclass.
9 .
Differentiate between for loop and while loop in C?
In C language, both 'for' loop and 'while' loop are used to repeatedly executing a set of instructions.

The main differences between both the loops are given below :

For loop While loop
The for loop can be declared as:
for(initialization; condition; iteration)
{
//loop body;
}
The while loop can be declared as:
while(condition){
statements;
}
We use for loop when we know the number of iterations. We use while loop when we do not know the number of iterations.
If the condition is not given in for loop, then it will execute for infinite times. If the condition is not given in while loop, then it will give the compilation error.
In for loop iteration, statement is written at the top of the loop so it will execute when all the loop body statements are executed. In while loop, the iteration statement can be placed anywhere inside the loop.
10 .
Differentiate between Set and List?
The Set and List, both are the interfaces which extend the Collection interface.

The primary differences between Set and List are given below :

Set List
The Set interface is an unordered collection of data elements The List interface is an ordered collection of data elements.
The Set interface does not contain any duplicate element, i.e., it only holds unique elements. The List interface can include duplicate elements
The Set interface does not maintain insertion order, or it can store elements in sorted order. The List interface maintains insertion order of data elements, that means element will store in the order in which they are inserted.
The primary implementation of the Set interface are HashSet, TreeSet, and LinkedHashSet. The primary implementations of the List interface are ArrayList, Vector, and LinkedList.
11 .
Write a program to swap two numbers without using any third variable?
#include <stdio.h>     
int main()   
{   
int a = 30, b = 20;   
 
printf("Before Swapping: a= %d, b= %d", a, b);   
 
// Code to swap 'x' and 'y'   
a= a + b;  // a becomes 50  
b= a - b;  // b becomes 30  
a = a- b;  // a becomes 20  
printf("\nAfter Swapping: a = %d, b = %d", a, b);   
return 0;   
}

Output :
Before Swapping: a= 30, b= 20
After Swapping: a = 20, b = 30
12 .
What is copy constructor and assignment operator?
Copy Constructor : Copy constructor is a constructor which creates an object by initializing it with a previously created object of same class.

It is called as a copy constructor because it has the same name as class name and it creates a copy of the previously created object.

Syntax :
Class_Name (const Class_Name & objectname)   
{  
//body....  
} 

Assignment Operator : Assignment operator is an operator which is called when an already initialized object is assigned a new value from another previously created object.

Syntax :
Class_Name Obj1, Obj2;   
Obj2= Obj1;   
13 .
What do you understand by Data Definition Language in SQL?
The SQL is a database language, by which we can perform various operations on an already created database. We can also create a new database with the help of various commands. These commands are categorized into four ways, one of them is DDL, which is termed as data definition language.

DDL contains such commands which are used for defining the database schema. It deals with the description of database schema and specifies the way of putting data in the database.

Following are some commands used by DDL :

CREATE : It is used for the creation of a database or its object.

ALTER : It is used to change the structure of the existing database.

DROP : It is used to drop/delete objects from the database.

TRUNCATE : It is used for removing all records, including all spaces, from a table.

COMMENT : It is used to add comments.

RENAME : It is used to rename an object from the database.
14 .
What do you understand by TRUNC and ROUND function?
TRUNC() function : The TRUNC() function is used to truncate or delete the certain number right to the decimal without rounding off.

Syntax :
TRUNC(n, decimal_number)  
Where, n = return a truncated number

decimal_number= nth of decimal place to truncated.


Example :
SQL> SELECT TRUNC (12.1256, 1) "TRUNC" FROM DUAL;   
 
TRUNC  
------------------------  
12.1  

ROUND () function : The ROUND() function is used to round-off any input value to its nearest integer value or the defined number of decimal points.

Syntax :
ROUND (n, decimal number)   
Where n= return a rounded number

decimal_number= It specifies the nth decimal place.


Example :
SQL> SELECT ROUND (10.2856, 1) "ROUND" FROM DUAL;   
    
    ROUND  
   -----------------  
    10.3  
15 .
Differentiate between overloading and overriding?
Method Overloading Method Overriding
When methods of the same class have the same name but different parameters or different return type, it is called method overloading. When the subclass has the same method as superclass method which contains the exact same name, same parameter and same return type, then it is called method overriding.
We can achieve compile-time polymorphism with method overloading. We can achieve runtime polymorphism with method overriding.
To obtain method overloading, methods must be of same class To obtain method overriding, methods must have a parent-child relationship.
The method parameters must be different in method overloading. The method parameter must be same in method overriding.
In Method overloading, return type can be of the same type or of different type. In method overriding, return type must be of the same type.
16 .
Differentiate between the Switch Statement and if else statement?
Both switch statement and if-else statement are used for selection of statement for a particular condition.

Main differences between both are given below :

SWITCH statement IF-ELSE statement
The execution of the statement is decided by the user. The execution of the statement depends upon the output of expression given inside if statement.
The switch statement uses single expression for multiple selections. The If-else statement uses multiple statements for multiple choices.
A Switch statement can only evaluate the character or integer value. If-else statement can evaluate integer, float, character, pointer, or Boolean values.
In switch statement, one case will be executed and then another if there is no any break statement. In if-else statement, either if statement will be executed or else statement.
17 .
What do you understand by ConcurrentMap?
The ConcurrentMap is an Interface, which extends Map interface. The ConcurrentMap interface is a member of the Java Collections framework. It is capable of handling concurrent access and provide thread safety.

Syntax :

public interface ConcurrentMap <K,V> extends Map<K,V>  

Where K and V are the parameters, which represents

K= the type of Keys

V= the type of value mapped with Keys
18 .
What do you understand by Hashtable?
In Java, Hashtable is a class which implements hash table data structure. It maps keys to value. For retrieving and storing objects from a Hashtable, every object which is used as a key, must implement the hashcode method and equals method.

Following are some main points for Hashtable :

* A Hashtable is an array of the list, which is termed as a bucket. To identify the position of the bucket we need to call the hashcode() method.
* Hashtable class contains unique elements in the list.
* It is the same as HashMap, but it is synchronized.

Syntax :

public class Hashtable<K,V> extends Dictionary<K,V> implements Map<K,V>, Cloneable, Serializable
19 .
Differentiate between static and init block in Java?
Static block is only executed at the first time of creation of a class object by JVM whereas init block is executed at every time whenever JVM creates the class Object. If in a class both static and init blocks are given then firstly static block will be executed and then init block.

Example :
class BlockBuild{  
   
 static{  
  System.out.println("This is Static block");  
 }  
   
 {  
  System.out.println("This is init block");  
 }  
 public static void main (String[] args) {  
 BlockBuild b= new BlockBuild();  
 new BlockBuild();  
 new BlockBuild();  
 new BlockBuild();  
 }  
}
 
Output :
This is Static block
This is init block
This is init block
This is init block
This is init block
20 .
What do you understand by the interface and abstract class?
Interface : Interface is like a class which has methods and variables, but all the methods declared in an Interface are abstract in nature. Interface in Java is a way to achieve abstraction and multiple inheritance.

To declare an interface in Java, we use 'interface' keyword. With the help of interface, we can achieve complete abstraction.

Syntax :
interface <interface_name>{   
    
 // declare constant fields   
 // declare methods that abstract   
 // by default.   
}


Abstract class : Use of an abstract class is another way to achieve abstraction in Java. For the creation of an abstract class, an 'abstract' keyword is used. With an abstract class, we can achieve complete or partial abstraction, which means it can have abstract or non-abstract methods. An abstract class cannot be instantiated.

Syntax :
abstract class Class_Name {  
 // Body   
 } 
21 .
How do you implement a semaphore in an operating system?
A semaphore is a synchronization object that is used to control access to a shared resource in a multi-threaded program. A semaphore has a count value that is incremented or decremented to indicate the availability of the shared resource. When a thread acquires a semaphore, the count value is decremented, and when the semaphore is released, the count value is incremented.

To implement a semaphore in an operating system, you can use a variety of techniques, depending on the specific needs of your program. Some common approaches include:

* Using a lock variable : One way to implement a semaphore is to use a lock variable that is set to "locked" when the semaphore is acquired, and "unlocked" when the semaphore is released. When a thread attempts to acquire the semaphore, it can check the value of the lock variable and block if it is set to "locked". This approach is simple, but may not be suitable for multi-processor systems.
Using a lock variable to implement a semaphore is not the correct approach because it does not provide the necessary functionality for allowing multiple threads to access a shared resource. A lock variable only allows one thread to acquire the lock at a time, which would defeat the purpose of using a semaphore to coordinate access to a shared resource.

Instead, a semaphore should use a counter variable that is incremented or decremented to indicate the availability of the shared resource. The counter variable should be initialized to the maximum number of threads that can access the resource simultaneously. When a thread wants to access the shared resource, it attempts to acquire the semaphore by decrementing the counter. If the counter is greater than zero, the thread can access the resource. If the counter is zero, the thread must block until another thread releases the semaphore by incrementing the counter.

This approach allows multiple threads to access the shared resource simultaneously, up to the maximum number specified by the counter variable. It also ensures that threads are blocked when the shared resource is unavailable and unblocked when it becomes available, allowing for efficient coordination of access to the resource.

* Using a kernel semaphore : Some operating systems provide kernel-level semaphores, which are implemented using low-level synchronization mechanisms such as atomic operations or hardware locks. Kernel semaphores can be more efficient than user-level semaphores, but are more difficult to use and may have stricter restrictions on their usage.

* Using a mutex and a condition variable : A mutex (short for "mutual exclusion") is a synchronization object that is used to protect shared resources from concurrent access, while a condition variable is a synchronization object that is used to signal the occurrence of a particular condition. Together, a mutex and a condition variable can be used to implement a semaphore by using the mutex to protect the count value and the condition variable to signal changes in the count value.

There are several different ways to implement a semaphore in an operating system, and the best approach depends on the specific needs of your program. Regardless of the technique you choose, it is important to ensure that your semaphore implementation is thread-safe and provides the necessary synchronization to control access to the shared resource.
22 .
How do you implement a mutex in an operating system?
A mutex (short for "mutual exclusion") is a synchronization object that is used to protect shared resources from concurrent access in a multi-threaded program. When a thread acquires a mutex, it prevents other threads from accessing the shared resource until the mutex is released.

To implement a mutex in an operating system, you can use a variety of techniques, depending on the specific needs of your program. Some common approaches include:

* Using a lock variable : One way to implement a mutex is to use a lock variable that is set to "locked" when the mutex is acquired, and "unlocked" when the mutex is released. When a thread attempts to acquire the mutex, it can check the value of the lock variable and block if it is set to "locked". This approach is simple, but may not be suitable for multi-processor systems.

* Using a semaphore : Another way to implement a mutex is to use a semaphore, which is a synchronization object that controls access to a shared resource. A semaphore can be used to implement a mutex by setting the value of the semaphore to 1, and using the "wait" and "signal" operations to acquire and release the mutex.

* Using a spinlock : A spinlock is a type of mutex that continuously spins in a loop, checking the status of the mutex, until it can acquire the mutex. This approach can be efficient but can consume a lot of CPU time if the mutex is held for a long time.

* Using a kernel mutex : Some operating systems provide kernel-level mutexes, which are implemented using low-level synchronization mechanisms such as atomic operations or hardware locks. Kernel mutexes can be more efficient than user-level mutexes, but are more difficult to use and may have stricter restrictions on their usage.

There are several different ways to implement a mutex in an operating system, and the best approach depends on the specific needs of your program. Regardless of the technique you choose, it is important to ensure that your mutex implementation is thread-safe and provides the necessary synchronization to protect shared resources.
23 .
Can you explain the difference between a UNION and a UNION ALL in SQL?
In SQL, the UNION and UNION ALL clauses are used to combine the results of two or more SELECT statements into a single result set. However, they are used in slightly different ways and serve different purposes.

The UNION clause is used to combine the results of two or more SELECT statements, but only includes unique rows in the final result set. This means that if a row appears in more than one SELECT statement and is included in the final result set, it will only be included once.

Here is an example of how you might use a UNION clause in SQL :
SELECT * FROM table1
UNION
SELECT * FROM table2;

This SQL statement will return all rows from both the "table1" and "table2" tables, but will only include unique rows in the final result set.

The UNION ALL clause is similar to the UNION clause, but includes all rows in the final result set, regardless of whether they are duplicates or not.

Here is an example of how you might use a UNION ALL clause in SQL :

SELECT * FROM table1
UNION ALL
SELECT * FROM table2;

This SQL statement will return all rows from both the "table1" and "table2" tables, including any duplicates.

The UNION and UNION ALL clauses are useful tools for combining the results of multiple SELECT statements in SQL, but are used in slightly different ways and serve different purposes. Understanding the differences between these two clauses can help you use them effectively in your SQL queries.
24 .
Can you explain the difference between a primary and a foreign key in a database?
In a database, a primary key is a field or set of fields that uniquely identifies each row in a table. A foreign key is a field or set of fields in one table that refers to the primary key of another table.

Here is an example of how primary and foreign keys can be used in a database:

Consider a database with two tables: a "customers" table and an "orders" table. The "customers" table might contain fields for the customer's ID, name, address, and phone number, while the "orders" table might contain fields for the order ID, customer ID, product ID, and quantity.

In this example, the customer ID field in the "customers" table could be used as the primary key, since it uniquely identifies each customer. The customer ID field in the "orders" table could then be used as a foreign key, since it refers to the primary key (customer ID) in the "customers" table.

By using primary and foreign keys in this way, the database can establish relationships between the two tables and ensure that the data is consistent and accurate. For example, if a customer's name or address changes in the "customers" table, that change will be automatically reflected in the "orders" table, since the "orders" table uses the customer ID as a foreign key to refer to the "customers" table.

Overall, primary and foreign keys are important concepts in database design, and are used to establish relationships between tables and ensure the integrity and accuracy of the data in the database.

Here is a comparison of primary and foreign keys in tabular form :

Property

Primary Key

Foreign Key

Definition

A field or set of fields that uniquely identifies each row in a table

A field or set of fields in one table that refers to the primary key of another table

Role in database

Establishes a unique identifier for each row in a table

Establishes a relationship between two tables by linking rows in one table to the primary key of another table

Example

Customer ID, order ID

Customer ID in orders table (refers to the primary key in customers table)



* Definition : A primary key is a field or set of fields that uniquely identifies each row in a table, while a foreign key is a field or set of fields in one table that refers to the primary key of another table.

* Role in database : Primary keys play a crucial role in establishing a unique identifier for each row in a table, while foreign keys are used to establish relationships between tables and link rows in one table to the primary key of another table.

* Example : In the example provided earlier, the customer ID field in the "customers" table could be used as the primary key, while the customer ID field in the "orders" table could be used as a foreign key to refer to the primary key in the "customers" table.

primary and foreign keys are important concepts in database design and are used to establish relationships between tables and ensure the integrity and accuracy of the data in the database. Understanding the differences between these two types of keys can help you design and use databases more effectively.
25 .
What is a database, and why is it important?
A database is a collection of data that is organized and stored in a structured way so that it can be accessed and manipulated efficiently. Databases are used to store and manage large amounts of data and are an important tool in a variety of settings, including business, government, and education.

There are several types of databases, including relational databases, which store data in tables with rows and columns, and object-oriented databases, which store data in the form of objects. While object-oriented databases do support the storage of complex data types and objects, they are not limited to just that data model. Object-oriented databases can also support other data models such as key-value or document-oriented databases.

In fact, many modern databases are designed to support multiple data models to provide greater flexibility and meet the needs of different applications. For example, some databases may support both relational and document-oriented data models, allowing developers to choose the model that best fits their data and application requirements.

Therefore, it is important to note that while object-oriented databases can store data in the form of objects, they are not limited to just that model, and can support a variety of different data models depending on the specific requirements of the application.

Some databases are designed to support specific applications, such as financial systems or inventory management, while others are more general-purpose and can be used for a wide range of applications.

In addition to databases designed for specific applications such as financial systems or inventory management, there are several other types of specialized databases designed for specific types of data and applications. Here are some examples:

* Time-series databases : These databases are designed for storing and analyzing time-series data, which is data that is collected over time at regular intervals. Examples of time-series data include stock prices, weather data, and website traffic. Time-series databases are optimized for handling large volumes of time-stamped data and for performing time-based queries and analyses.

* Graph databases : Graph databases are designed for storing and querying data that has a graph-like structure, such as social networks, recommendation engines, and knowledge graphs. Graph databases use graph theory to represent and query data, making it easy to navigate complex relationships between entities.

* Spatial databases : Spatial databases are designed for storing and querying geospatial data, such as maps, satellite imagery, and location data. Spatial databases use specialized algorithms and data structures to optimize queries that involve spatial data.

Other examples of specialized databases include document databases, which are designed for storing and querying semi-structured and unstructured data such as emails, PDFs, and JSON documents; and columnar databases, which are designed for storing and querying large amounts of structured data such as log files and transaction data.

One of the main reasons that databases are important is that they allow for the efficient storage and management of large amounts of data. By organizing data in a structured way, databases make it easy to retrieve, update, and manipulate data as needed. This is especially important for organizations that need to manage large amounts of data, such as customer records, sales data, or inventory information.

Another reason that databases are important is that they provide a way to ensure the integrity and security of data. Databases can be designed with security measures in place to prevent unauthorized access to data, and can also include features to help ensure that data is accurate and consistent.

Databases are an essential tool for storing, managing and accessing large amounts of data in a structured and efficient way. They play a critical role in a wide range of settings and are an important component of many modern computing systems.
26 .
Can you explain the difference between a bubble sort and a quick sort?
Bubble sort and quicksort are two algorithms for sorting a list of items. Both algorithms have their own strengths and weaknesses, and the choice of which algorithm to use will depend on the specific requirements of the task at hand.

Bubble sort is a simple and intuitive sorting algorithm that works by repeatedly iterating through the list and swapping adjacent elements if they are in the wrong order. It has a time complexity of O(n^2), which means that it takes longer to sort larger lists. However, it has a space complexity of O(1), which means that it only requires a constant amount of additional memory to perform the sort.

Here is an example of how bubble sort might be implemented in Python :
def bubble_sort(lst):
    n = len(lst)
    for i in range(n):
        for j in range(n - 1 - i):
            if lst[j] > lst[j + 1]:
                lst[j], lst[j + 1] = lst[j + 1], lst[j]

Quick sort is a more efficient sorting algorithm that works by partitioning the list into two sublists, sorting the sublists, and then merging the sorted sublists back together. It has a time complexity of O(n log n), which is significantly faster than bubble sort for larger lists. However, it has a space complexity of O(n), which means that it requires more memory to perform the sort.

Here is an example of how quick sort might be implemented in Python :
def quick_sort(lst):
    if len(lst) <= 1:
        return lst
    pivot = lst[0]
    left = [x for x in lst[1:] if x < pivot]
    right = [x for x in lst[1:] if x >= pivot]
    return quick_sort(left) + [pivot] + quick_sort(right)

Overall, bubble sort is a simple and easy-to-understand sorting algorithm that is suitable for small lists, while quick sort is a more efficient algorithm that is suitable for larger lists. The choice between these two algorithms will depend on the specific requirements of the task at hand.
27 .
Can you explain the difference between a shallow and a deep copy?
In Python, a shallow copy is a copy of an object that creates a new object with a new reference to the same underlying data, but does not create new copies of the data itself. A deep copy, on the other hand, creates a new object with a new reference to new copies of the data, as well as new copies of any nested objects within the original object.

Here is an example to illustrate the difference between a shallow and a deep copy in Python:
import copy

# Create a list with nested lists
original_list = [[1, 2, 3], [4, 5, 6]]

# Create a shallow copy of the list
shallow_copy = copy.copy(original_list)

# Create a deep copy of the list
deep_copy = copy.deepcopy(original_list)

# Modify the original list
original_list[0][0] = 7

print(original_list)   # [[7, 2, 3], [4, 5, 6]]
print(shallow_copy)    # [[7, 2, 3], [4, 5, 6]]
print(deep_copy)       # [[1, 2, 3], [4, 5, 6]]

In this example, the original list contains two nested lists. When the shallow copy is created, a new object is created with a new reference to the same data, but the nested lists are not copied. When the deep copy is created, a new object is created with a new reference to new copies of the data, including the nested lists. When the original list is modified, the changes are reflected in the shallow copy but not in the deep copy.
28 .
How do you implement a linked list in code?
A linked list is a linear data structure that consists of a sequence of nodes, where each node contains a data element and a reference (link) to the next node in the sequence. Linked lists are often used to implement lists, stacks, and queues, as they can be easily inserted or removed in constant time.

Here is an example of how you might implement a linked list in Python :
class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

The Node class represents a single node in the linked list and contains a data element and a reference to the next node in the sequence. The LinkedList class represents the linked list itself and contains a reference to the head of the list (the first node).

To add a new node to the linked list, you can use the append method :
def append(self, data):
    new_node = Node(data)
    if self.head is None:
        self.head = new_node
        return
    current_node = self.head
    while current_node.next:
        current_node = current_node.next
    current_node.next = new_node

This method creates a new Node object with the given data and appends it to the end of the linked list by updating the next reference of the last node in the list.

To remove a node from the linked list, you can use the delete method :
def delete(self, data):
    current_node = self.head
    if current_node.data == data:
        self.head = current_node.next
        return
    prev_node = None
    while current_node.data != data:
        prev_node = current_node
        current_node = current_node.next
    prev_node.next = current_node.next

Overall, implementing a linked list involves creating classes for the nodes and the list itself, and defining methods for inserting and deleting nodes.

Publicis Sapient MCQ :

1 .
Find the antonym for word 'NADIR'?
A)
Liberty
B)
Progress
C)
Zenith
D)
Modernity

Correct Answer :   Zenith

2 .
What will be the Synonym for word 'FORAY'?
A)
Maraud
B)
Ranger
C)
Contest
D)
Intuition

Correct Answer :   Maraud

3 .
Sujit and Udit are twins brother, but they do not look_______
A)
Likely
B)
Alike
C)
Unique
D)
Different

Correct Answer :   Alike

4 .
Find the odd one out from the following:
A)
Arc
B)
Radius
C)
Tangent
D)
Diagonal

Correct Answer :   Diagonal

5 .
Probe: Wound :: Anemography:?
A)
Force
B)
Rainfall
C)
Pressure
D)
Humidity

Correct Answer :   Force

6 .
Find the antonym for the word 'FLAGITIOUS'?
A)
Vapid
B)
Ignorant
C)
Innocent
D)
Frivolous

Correct Answer :   Innocent

7 .
It's very kind of you to ________ to speak at the lecture hall.
A)
Concur
B)
Agree
C)
Accept
D)
Comply

Correct Answer :   Agree

8 .
Complete the sentence with appropriate phrase:
Rohan always stammers in public meetings, but his today's speech_____________
A)
Was very boring
B)
Was fairly audible to everyone
C)
Was not audible correctly
D)
Was better than previous speech

Correct Answer :   Was fairly audible to everyone

9 .
Two trains are running with the speed of 60 km/hr and 40 km/hr respectively in the same direction. The Fast moving train completely passes a man sitting in slower train in 9 sec. Find the length of the fast moving train.
A)
33m
B)
44m
C)
50m
D)
60m

Correct Answer :   50m


Explanation : Relative speed of both train = (60-40) km/hr = 20 km/hr

20km/hr= 20*(5/18) m/sec = 100/18m/sec

So the length of fast moving train= (100/18)*9= 50m.

10 .
If log 27= 1.431, then what will be the value of log 9?
A)
0.654
B)
0.754
C)
0.854
D)
0.954

Correct Answer :   0.954


Explanation : log(3)3 = 1.431

3 log 3= 1.431

log 3 = 0.477

log 9= log(3)2= 2 log 3 = 2*0.477= 0.954

11 .
The balls in a bag are numbered from 1 to 20 and mixed up. If one ball is drawn out randomly then what is the probability that the drawn ball has a number, which is a multiple of 3 or 5?
A)
1/2
B)
1/3
C)
7/20
D)
9/20

Correct Answer :   9/20


Explanation : Total number of multiple of 3 upto 20 = 20/3= 6 (only taking whole number)

Total number of multiple of 5 upto 20= 20/5 = 4

Total number of 3*5 upto 20= 1

So total multiple upto of 3 or 5 upto 20= 6+4-1= 9

So required probability = 9/20

12 .
To complete a piece of work A takes twice the time of B and thrice the time of C. If all working together can finish the same work in 8 days, then how many days are required to finish the work by B alone?
A)
16 days
B)
24 days
C)
40 days
D)
48 days

Correct Answer :   24 days


Explanation : As per the question,

Suppose, A takes X days to finish a piece of work, so B will take X/2 days, and C will take X/3 days

Then, (1/X+2/X+3/X) = 1/8

Solving the above equation:

6/x= 1/8

X= 48 days

So B alone can finish the work in 48/2= 24 days.

13 .
If log 2= 0.30103, then what will be the number of digits in 2^64?
A)
18
B)
19
C)
20
D)
21

Correct Answer :   20


Explanation : To find the number of digits in 2^64 take the log of the number

log(2^64)= 64*log 2= 64*0.30103= 19.26592

Its characteristic is 19 hence to obtain the digit we need to add in characteristic.

Hence total number of digits= 19+1= 20.

14 .
Rahul purchased 12 dozens of toys at the rate of Rs.300 per dozen. He sold each of toys at the rate of Rs.29. What is his percentage profit?
A)
13.5%
B)
15%
C)
16%
D)
18%

Correct Answer :   16%


Explanation : Cost price of 1 toy = 300/12= Rs.25

Selling price of 1 toy = Rs.29

Gain = S.P.-C.P. =29-25= Rs.4

Profit %= 4*100/25= 16%

15 .
In how many ways can letter of word CORPORATION can be arranged so that all vowels always come together?
A)
50400
B)
5760
C)
2886
D)
None of the Above

Correct Answer :   50400


Explanation : The word CORPORATION have 5 vowels which are 'O', 'O', 'A', 'I', 'O'. So grouping all vowels together, we can consider all the vowels as 1 letter

So it can be arranged as CRPRTN(OOAIO)

It has 7 letter so can be arranged as !7 in which R is 2 times so

!7/!2

And again we can arrange all the vowels in !5/!3 ways

So total number of ways = (!7/!2)*(!5/!3) = 50400

16 .
Find the smallest number which leaves a remainder of 2, when divided by 3, 4, 5, and 6?
A)
32
B)
45
C)
56
D)
62

Correct Answer :   62


Explanation : Taking L.C.M of 3, 4, 5 and 6 = 60

Hence, 60 is the number which is completely divisible by these number, but we need that number which leaves the remainder of 2 while dividing by these number, so the required number is 62.

17 .
A running train passes a pole in 15 seconds and a platform of 100 m long in 25 seconds. Find the length of the train.
A)
50 m
B)
150 m
C)
200 m
D)
Insufficient data

Correct Answer :   150 m


Explanation : Let's suppose train is running with a speed of X m/sec having a length of x meters, so

Speed = length/time

s= x/15 (while passing a pole) ........... (i)

s= (x+100)/25(while passing the platform)...........( ii)

Equating both equations, we get

x/15= (x+100)/25

5x=300+3x

2x=300

x=150 meters

18 .
If in a coding language A=1 and FAT = 27, then ACT =?
A)
20
B)
23
C)
24
D)
25

Correct Answer :   24


Explanation : As A= 1 so F=6, And T= 20

So FAT = 1+6+20= 27

Hence, ACT = 1+3+20= 24

19 .
Pointing towards a girl, Rahul said, 'She is the only daughter of my grandfather's only child,' then how that girl is related to Rahul?
A)
Sister
B)
Niece
C)
Daughter
D)
Insufficient Data

Correct Answer :   Sister

20 .
Find the missing number in the series.
1, 2, 6, 24, ?, 720.
A)
100
B)
104
C)
108
D)
120

Correct Answer :   120


Explaination : In the given Sequence, each number follow the pattern of:

1*1=1, 1*2=2, 2*3=6, 6*4=24, 24*5= 120, and 120*6= 720.

21 .
Find the missing number in the series.
5760, 960, ?, 48, 16, 8.
A)
240
B)
192
C)
160
D)
120

Correct Answer :   192


Explaination : The given series follows a pattern of,

5760/6=960, 960/5= 192, 192/4= 48, 48/3=16, and 16/8= 2.

22 .
PLAY is related to ACTOR, so CONCERT is connected to?
A)
Piano
B)
Musician
C)
Percussion
D)
Symphony

Correct Answer :   Musician

23 .
An assembler converts an assembly code to machine language code:
A)
Between the execution
B)
After the computer can execute the code
C)
Before the computer can execute the code
D)
All of the above

Correct Answer :   Before the computer can execute the code

24 .
Which is not a derived data type from below options:
A)
Enum Types
B)
Array types
C)
Union Types
D)
Pointers Types

Correct Answer :   Enum Types

25 .
How to calculate the square of a variable 'x' in C?
A)
Sqr(x)
B)
pow(x,2)
C)
power(x,2)
D)
power(2,x)

Correct Answer :   pow(x,2)

26 .
The default parameter passing technique is
A)
Call by value
B)
Call by reference
C)
Call by value result
D)
None of the above

Correct Answer :   Call by value

27 .
Which of following traversal of Binary search tree give the output values in sorted order?
A)
In order
B)
Post-order
C)
Pre-order
D)
None of the above

Correct Answer :   Pre-order

28 .
The retrieval of items in the stack is which type of operation?
A)
push
B)
access
C)
retrieval
D)
pop

Correct Answer :   pop

29 .
If new data needs to be inserted into data-structure, but there is no more space then this situation is called as:
A)
OverLeak
B)
Overflow
C)
Memory full
D)
Memory Leak

Correct Answer :   Overflow

30 .
Binary search can have maximum comparisons of ________?
A)
n
B)
2*log n
C)
log(n)+1
D)
(n+1)/2

Correct Answer :   log(n)+1