Sum of Numbers C++

Sum of Numbers
Write a function that accepts an integer argument and returns the sum of all the integers
from 1 up to the number passed as an argument. For example, if 50 is passed as
an argument, the function wi ll return the sum of 1, 2, 3, 4, … 50. Use recursion to calculate the sum. 

Answer:

//  Sum of Numbers
#include <iostream>
using namespace std;

// Function prototype
int sum(int);

int main()
{
	// Let's get the sum of the integers
	// 1 through 50...
	cout << sum(50) << endl;
        return 0; 
} 
//*******************************************
// The sum function returns the sum of the * 
// integers 1 through max.                 * 
//*******************************************
int sum(int max)
{ 
        if (max > 0)
		return max + sum(max - 1);
	else
		return 0;
}