C program to find sum of array elements using recursion

Write a C program to find sum of array elements using recursion. How to find sum of array elements using recursive function in C programming. Logic to find sum of array elements using recursion in C program.

Input size of array: 10
Input array elements: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Sum of array: 55

Required knowledge

Basic C programming, If else, Functions, Recursion, Array

Must know – Program to find sum of array elements using loop

Program to print sum of array elements using recursion

/**
 * C program to find sum of array elements using recursion
 */

#include <stdio.h>
#define MAX_SIZE 100

/* Function declaration to find sum of array */
int sum(int arr[], int start, int len);


int main()
{
    int arr[MAX_SIZE];
    int N, i, sumofarray;
    
    
    /* Input size and elements in array  */
    printf("Enter size of the array: ");
    scanf("%d", &N);
    printf("Enter elements in the array: ");
    for(i=0; i<N; i++)
    {
        scanf("%d", &arr[i]);
    }
    
    
    sumofarray = sum(arr, 0, N);
    printf("Sum of array elements: %d", sumofarray);
    
    return 0;
}


/**
 * Recursively find the sum of elements in an array.
 */
int sum(int arr[], int start, int len) 
{
    /* Recursion base condition */
    if(start >= len)
        return 0;
        
    return (arr[start] + sum(arr, start + 1, len));
}

Enter size of the array: 10
Enter elements in the array: 1 2 3 4 5 6 7 8 9 10
Sum of array elements: 55

Happy coding 😉