UVALive

用栈消去已经完美的括号，剩下的分两种情况处理就是了

#include <iostream>#include <cstdio>#include <string>#include <cstring>#include <algorithm>#include <cmath>#include <queue>#include <vector>#include <set>#include <stack>#include <map>#include <climits>using namespace std;typedef long long ll;const int maxn = 100 + 7, INF = 0x3f3f3f3f, mod = 1e9 + 7;stack<char> sk;char s[maxn];int n;int main() {    int T; scanf("%d", &T);    while(T--) {        scanf("%d%s", &n, s);        for(int i = 0; i < n; ++i) {            if(!sk.empty()) {                if(s[i] == ')') {                    if(sk.top() == '(') sk.pop();                    else sk.push(s[i]);                }                else sk.push(s[i]);            }            else sk.push(s[i]);        }        int ans = 0;        while(!sk.empty()) {            char c1 = sk.top(), c2;            sk.pop();            if(!sk.empty()) c2 = sk.top(), sk.pop();            if(c1 == c2) ans ++;            else ans += 2;            //cout << ans << " == " << endl;        }        cout << ans << endl;    }    return 0;}