洛谷 P3952 时间复杂度 (C/C++)

洛谷 P3952 时间复杂度

#include <iostream>
#include <cstdio>
#include <stack>
#include <set>
#include <string>
using namespace std;
int getNumber(string s) {
  int res = 0;
  for(int i = 0; i < s.length(); i++) {
    res *= 10;
    res += s[i] - '0';
  }
  return res;
}
int getO(string s) {
  int res = 0;
  if(s[2] == '1') return 0;
  for(int i = 4; s[i] != ')'; i++) {
    res *= 10;
    res += s[i] - '0';
  }
  return res;
}
int main() {
  int t; cin >> t;
  stack<int> cache;
  for(int i = 0; i < t; i++) {
    int l; string o;
    scanf("%d", &l); cin >> o;
    stack<string>name;
    set<string>check_name;
    int finallyO = 0, tempO = 0;
    bool flag = true, alone = false;
    int EFs = 0;
    for(int j = 0; j < l; j++) {
      char ch; getchar();
      scanf("%c", &ch);
      if(ch == 'E') {
        EFs -= 1; tempO -= 1;
        if(!name.empty()) {
          check_name.erase(name.top()); name.pop();
        }
        if(!EFs) {
          alone = false;
          tempO = 0;
        }
      } else if(ch == 'F') {
        EFs += 1;
        string v, x, y; cin >> v >> x >> y;
        if(check_name.find(v) != check_name.end()) flag = false;
        else {
          check_name.insert(v);
          name.push(v);
          if(x[0] >= '0' && x[0] <= '9' && y[0] == 'n') {
            if(!alone) tempO++;
            finallyO = max(finallyO, tempO);
          } else if(x[0] == 'n' && y[0] >= '0' && y[0] <= '9'
                    || getNumber(x) > getNumber(y))
                    alone = true;
        }
      }
    }
    if(EFs || !flag) puts("ERR");
    else if(getO(o) == finallyO) puts("Yes");
    else puts("No");
  }

  return 0;
}