Enqueue Operation in DSA C - Build from Scratch

Enqueue Operation in a Queue

📖 Scenario: Imagine a line at a ticket counter where people join at the end of the line. This line is called a queue. We will create a queue using an array and add people (numbers) to the end of this queue.

🎯 Goal: You will build a simple queue using an array and write the code to add (enqueue) elements to the queue.

📋 What You'll Learn

Create an integer array called queue with size 5

Create an integer variable called rear initialized to -1

Write a function called enqueue that adds an integer to the queue if there is space

Print the queue elements after adding new elements

💡 Why This Matters

🌍 Real World

Queues are used in real life for lines, like waiting for a bus or at a bank. In computers, queues help manage tasks in order.

💼 Career

Understanding queues is important for software jobs that involve task scheduling, resource management, and data processing.

1

Create the queue array and rear variable

Create an integer array called queue with size 5 and an integer variable called rear initialized to -1.

DSA C

# Create the queue array and rear variable
// Your code here

Hint

Use int queue[5]; to create the array and int rear = -1; to start the rear pointer.

2

Create the enqueue function header

Write the function header for void enqueue(int value) that will add a value to the queue.

DSA C

int queue[5];
int rear = -1;

// Write the function header for enqueue
// Your code here

Hint

Start the function with void enqueue(int value) {

3

Implement enqueue logic to add element

Inside the enqueue function, check if rear is less than 4. If yes, increase rear by 1 and add value to queue[rear]. Close the function with a closing brace }.

DSA C

int queue[5];
int rear = -1;

void enqueue(int value) {
    // Your code here
}

Hint

Use if (rear < 4) to check space, then rear++ and assign queue[rear] = value;.

4

Add elements and print the queue

Call enqueue three times with values 10, 20, and 30. Then use a for loop from 0 to rear to print each element in queue separated by spaces.

DSA C

int queue[5];
int rear = -1;

void enqueue(int value) {
    if (rear < 4) {
        rear++;
        queue[rear] = value;
    }
}

int main() {
    // Your code here
    return 0;
}

Hint

Call enqueue(10); enqueue(20); enqueue(30); then print elements with a for loop and printf.