简单粗暴的题解

#include<bits/stdc++.h>
using namespace std;
int f(int a, int b){
    if(a % b == 0) return b;
    return f(b, a % b);
}
int main(){
	int n;
    cin >> n;
    int p[15] = {}, q[15] = {};
    for(int i = 1; i <= n; i++) {
        scanf("%d/%d", &p[i], &q[i]);
    }
    int sum = 1, maxn = q[1], t;
    for(int i = 1; i <= n; i++){
        sum *= q[i];
        maxn = max(maxn, q[i]);
    }
    for(int i = maxn; i <= sum; i++) {
        int flag = 1;
        for(int j = 1; j <= n; j++) {
            if(i % q[j]) {
                flag = 0;
                break;
            }
        }
        if(flag){
            t = i;
            break;
        }
    }
    int a = 0, b = t;
    for(int i = 1; i <= n; i++){
        a += p[i] * (b / q[i]);
    }
    int c = f(a, b);
    int t1 = a / c, t2 = b / c;
    if(t1 % t2 == 0) cout << t1 / t2;
    else cout << t1 << '/' << t2;
	return 0;
}