C++ Program For Sum of Natural Numbers Using Recursion
Last Updated :
23 Jun, 2023
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Natural numbers include all positive integers from 1 to infinity. It does not include zero (0). Given a number n, find the sum of the first n natural numbers. To calculate the sum, we will use the recursive function recur_sum().
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Examples:
Input: 3
Output: 6
Explanation: 1 + 2 + 3 = 6Input: 5
Output: 15
Explanation: 1 + 2 + 3 + 4 + 5 = 15
The Sum of Natural Numbers Using Recursion
Below is a C++ program to find the sum of natural numbers up to n using recursion:
// C++ program to find the sum
// of natural numbers up to n
// using recursion
#include <iostream>
using namespace std;
// Returns sum of first
// n natural numbers
int recurSum(int n)
{
if (n <= 1)
return n;
return n + recurSum(n - 1);
}
// Driver code
int main()
{
int n = 5;
cout << recurSum(n);
return 0;
}
Output
15
