C++ or C program to find sum of n numbers using Recursion/Recursive function

File name:- sumnrec.cpp

#include <iostream.h>

#include<conio.h>

int main(){

int sum(int n);

int num, result;

clrscr();

cout<<"Enter a positive integer"<<endl;

cin>>num;

result = sum(num);

cout<<"sum= "<<result<<endl;

getch();

}

int sum (int n){

if(n!=0) return n + sum(n-1);

else return n;

}

File name:- sumnrec.c

#include <stdio.h>

#include<conio.h>

int main(){

int sum(int n);

int num, result;

clrscr();

printf("Enter a positive integer\n");

scanf("%d", &num);

result = sum(num);

printf("sum=%d", result);

getch();

}

int sum (int n){

if(n!=0) return n + sum(n-1);

else return n;

}