Sum of array elements using recursion
Given an array of integers, find sum of array elements using recursion.
Examples:
Input : A[] = {1, 2, 3}
Output : 6
1 + 2 + 3 = 6
Input : A[] = {15, 12, 13, 10}
Output : 50
We have discussed iterative solution in below post.
Sum of elements in a given array
In this post, recursive solution is discussed.
C++
#include <stdio.h>
int findSum( int A[], int N)
{
if (N <= 0)
return 0;
return (findSum(A, N - 1) + A[N - 1]);
}
int main()
{
int A[] = { 1, 2, 3, 4, 5 };
int N = sizeof (A) / sizeof (A[0]);
printf ( "%d" , findSum(A, N));
return 0;
}
|
Java
public class Test {
static int arr[] = { 1 , 2 , 3 , 4 , 5 };
static int findSum( int A[], int N)
{
if (N <= 0 )
return 0 ;
return (findSum(A, N - 1 ) + A[N - 1 ]);
}
public static void main(String[] args)
{
System.out.println(findSum(arr, arr.length));
}
}
|
Python3
def _findSum(arr, N):
if N < = 0 :
return 0
else :
return _findSum(arr, N - 1 ) + arr[N - 1 ]
arr = []
arr = [ 1 , 2 , 3 , 4 , 5 ]
N = len (arr)
ans = _findSum(arr,N)
print (ans)
|
C#
using System;
class Test {
static int []arr = {1, 2, 3, 4, 5};
static int findSum( int []A, int N)
{
if (N <= 0)
return 0;
return (findSum(A, N - 1) + A[N - 1]);
}
public static void Main()
{
Console.Write(findSum(arr, arr.Length));
}
}
|
PHP
<?php
function findSum( $A , $N )
{
if ( $N <= 0)
return 0;
return (findSum( $A , $N - 1) +
$A [ $N - 1]);
}
$A = array (1, 2, 3, 4, 5);
$N = sizeof( $A );
echo findSum( $A , $N );
?>
|
Javascript
<script>
function findSum(A, N) {
if (N <= 0)
return 0;
return (findSum(A, N - 1) + A[N - 1]);
}
let A = [1, 2, 3, 4, 5];
let N = A.length;
document.write(findSum(A, N));
</script>
|
Time Complexity; O(n)
Here n is the number of elements in the array.
Auxiliary Space: O(n)
The extra space is used in recursion call stack.
How does above recursive solution work?
This article is contributed by
Prakhar Agrawal.
Last Updated :
19 Sep, 2023
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