C Program to insert an element in an array

C Program to insert an element in an array.

Suppose there is an array of length N . We want to insert an element in the array at index i (0<=i<=N-1). After inserting element number of element will be increased by 1. To insert an element in array at the index i we have to shift all elements of array from i to N-1. to next index . An element from index position j will be moved to j+1.

For example, suppose there is an array ” a ” of length of 8 which contains 5 elements from a[0] to a[4]. We want to insert 25 at index position a[3]. So we have to move every elements from a[3] to a[4] to next index position in the array.

Move a[4] to a[5]

Move a[3] to a[4]

Insert 25 at a[3]

C Program to insert an element in an array : Source Code

/******************************************************************************

C Program to insert an element in an array

https://bptutorials.com

*******************************************************************************/
#include <stdio.h>
#include <conio.h>
 
int main(){
    int arr[400], totalElement, cntr, element, indexPos;
     
    printf("Enter number of total elements in array: ");
    scanf("%d", &totalElement);
    printf("Enter %d numbers \n", totalElement);
     
    for(cntr = 0; cntr < totalElement; cntr++){
        scanf("%d", &arr[cntr]);
    }
     
    printf("Enter number to be inserted\n");
    scanf("%d", &element);
    printf("Enter index position where you want to insert an element\n");
    scanf("%d", &indexPos);
     
    /* Moving all elements right of index position by one position */
    for(cntr = totalElement; cntr > indexPos; cntr--){
        arr[cntr] = arr[cntr-1];
    } 
    arr[indexPos] = element;
    /* Print array after inserting element */
    printf("Updated Array\n");
    for(cntr = 0; cntr < totalElement + 1; cntr++){
        printf("%d ", arr[cntr]);
    }
         
    getch();
    return 0;
} 

Output :

Enter number of total elements in array: 6
Enter 6 numbers 
15 10 25 7 9 23
Enter number to be inserted
14
Enter index position where you want to insert an element
5
Updated Array
15 10 25 7 9 14 23