【习题 6-1 UVA-673】Parentheses Balance

#include <bits/stdc++.h>
using namespace std;

const int N = 150;

stack <char> sta;
string s;

int main() {
    #ifdef LOCAL_DEFINE
        freopen("F:\\c++source\\rush_in.txt", "r", stdin);
    #endif
    ios::sync_with_stdio(0),cin.tie(0);
    int T;
    cin >> T;cin.get();
    while (T--) {
        while (!sta.empty()) sta.pop();
        getline(cin,s);
        int n= s.size();
        int ok = 1;
        for (int i = 0;i < n;i++){
            if (s[i]=='(' || s[i] == '[')
                sta.push(s[i]);
            else if (!sta.empty() && sta.top()=='(' && s[i]==')') sta.pop();
                else if (!sta.empty() && sta.top()=='[' && s[i]==']') sta.pop();
                    else ok = 0;
        }
        if (!sta.empty()) ok = 0;
        if (!ok){
            cout << "No" << endl;
        }else{
            cout << "Yes"<<endl;
        }
    }


    return 0;
}