sum_of_n_natural_number_recursion.cpp

#include<iostream>
using namespace std;

int sum(int n)
{
    if(n==0)
    {
        return 0;
    }
   return n + sum(n-1); 
}

int main()
{
    int n;
    cout<<"Enter the number till where you need sum: ";
    cin>>n;
    cout<<sum(n)<<endl;

    return 0;
}