C PROGRAMMING PROGRAM • ARRAYS, SEARCHING & SORTING

Rotate an Array Left by One Position

Learn how to rotate an array left by one position using a clear C program.

BeginnerArraysRotationShift

PROBLEM UNDERSTANDING

Input and expected output

Sample input

5
1 2 3 4 5

Sample output

2 3 4 5 1

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int size, values[100];

    printf("Enter array size: ");
    scanf("%d", &size);
    if (size < 1 || size > 100) return 1;
    for (int index = 0; index < size; index++) scanf("%d", &values[index]);
    int first = values[0];
    for (int index = 0; index < size - 1; index++) values[index] = values[index + 1];
    values[size - 1] = first;
    for (int index = 0; index < size; index++) printf("%d%c", values[index], index == size - 1 ? '\n' : ' ');
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

2 3 4 5 1

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Save the first element, shift the others left and place the saved value at the end.
Display the computed result.

Save the first element, shift the others left and place the saved value at the end.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

Check this

Use the correct format specifier for every variable.

Check this

Initialize variables before using their values.

Check this

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.