DATA STRUCTURES PROGRAM • QUEUES & DEQUES

Implement a Linear Queue Using an Array

Learn how to implement a linear queue using an array using a clear C program.

BeginnerQueueFIFOfront/rear

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

Removed = 10
Front = 20

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int queue[10], front = 0, rear = 0;
    queue[rear++] = 10; queue[rear++] = 20; queue[rear++] = 30;
    printf("Removed = %d\n", queue[front++]);
    printf("Front = %d\n", queue[front]);
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Removed = 10
Front = 20

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Insert at rear and remove at front while maintaining two indices.
Display the computed result.

Insert at rear and remove at front while maintaining two indices.

EFFICIENCY

Time and space complexity

Time complexity

O(1) per operation

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.