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C program to swap adjacent elements of a one dimensional array

Problem statement

Given N array elements and we have to swap adjacent elements using C program.

Swapping adjacent elements of a one dimensional array

In this C program, we are going to learn how to swap adjacent elements of a given array of N elements?

Example

Enter total number of elements: 10
Enter array elements:
Enter element 1: 10
Enter element 2: 20
Enter element 3: 30
Enter element 4: 40
Enter element 5: 50
Enter element 6: 60
Enter element 7: 70
Enter element 8: 80
Enter element 9: 90
Enter element 10: 100

Array elements after swapping adjacent elements:
20
10
40
30
60
50
80
70
100
90

C program to swap adjacent elements of a one dimensional array

/*C program to swap adjacent elements of an one dimensional array.*/
 
#include <stdio.h>
#define MAX 100
int main()
{
    int arr[MAX],n,i;
    int temp;
     
    printf("Enter total number of elements: ");
    scanf("%d",&n);
     
    //value of n must be even
    if(n%2 !=0)
    {
        printf("Total number of elements should be EVEN.");
        return 1;
    }
    //read array elements
    printf("Enter array elements:\n");
    for(i=0;i < n;i++)
    {
        printf("Enter element %d:",i+1);
        scanf("%d",&arr[i]);
    }
    //swap adjacent elements
    for(i=0;i < n;i+=2)
    {
        temp    = arr[i];
        arr[i]  = arr[i+1];
        arr[i+1]= temp;
    }
     
    printf("\nArray elements after swapping adjacent elements:\n");
    for(i=0;i < n;i++)
    {
        printf("%d\n",arr[i]);
    }
    return;
}

Output

First Run:
Enter total number of elements: 11
Total number of elements should be EVEN.

Second Run:
Enter total number of elements: 10
Enter array elements:
Enter element 1: 10
Enter element 2: 20
Enter element 3: 30
Enter element 4: 40
Enter element 5: 50
Enter element 6: 60
Enter element 7: 70
Enter element 8: 80
Enter element 9: 90
Enter element 10: 100

Array elements after swapping adjacent elements:
20
10
40
30
60
50
80
70
100
90

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