5-35 有理数均值 (20分)

#include<iostream>

using namespace std;

#define N 100

struct Rational{
	int n;  
	int d;
};
int gcd(int a, int b)
{
	int temp;
	if (a == 0 & b == 0)
	{
		return 0;
	}
	if (a == 0)
	{
		return b;
	}
	if (b == 0)
	{
		return a;
	}
	while (1)
	{
		temp = a%b;
		if (temp == 0)
		{
			return b;
		}
		a = b;
		b = temp;
	}
	
	return b;
}
int main(void)
{
	struct Rational ra[N],r;
	int n;
	cin>>n;
	for (int i = 0; i < n; i++)
	{
		scanf("%d/%d", &ra[i].n, &ra[i].d);
	}
	r.n = 0;
	r.d = 1;
	for (int i = 0; i < n; i++)
	{
		r.n = r.n*ra[i].d + r.d*ra[i].n;
		r.d = r.d*ra[i].d;
	}
	r.d *= n;  //平均值
	int g = gcd(r.n, r.d);
	if (g != 0)
	{
		r.n /= g;
		r.d /= g;
	}
	if (r.d == 1)
	{
		cout << r.n;
	}
	else if (r.n == 0)
	{
		cout << r.n;
	}
	else
	{
		cout << r.n << ‘/‘ << r.d;
	}
	
	return 0;
}