int sum(int val)//int sum2(int val) 间接递归

// DiGui.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
int sum2(int val);
int sum(int val)
{
	if(val==1)
		return 1;
	else
		return val+sum2(val-1);
}

int sum2(int val)
{
	if(val==1)
		return 1;
	else
		return val+sum(val-1);
}

int main(int argc, char* argv[])
{
	int n;
	n=5;
	printf("sum(%d)=%d\n",n,sum(n));
	n=5;
	printf("sum2(%d)=%d\n",n,sum2(n));
	return 0;
}

/*
sum(5)=15
sum2(5)=15
Press any key to continue
*/