Submission #729845

#	Time	Username	Problem	Language	Result	Execution time	Memory
729845		NeroZein	Election (BOI18_election)	C++17	0 / 100	22 ms	31724 KiB

election

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

signed main () {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); 
  int n;
  cin >> n;
  string s;
  cin >> s;
  vector<int> a(n); 
  for (int i = 0; i < n; ++i) {
    a[i] = (s[i] == 'C' ? 1 : -1); 
  }
  auto Or = [&](vector<int>& x, const vector<int>& y) {
    for (int i = 0; i < n; ++i) {
      x[i] |= y[i];
    }
  };
  vector<int> tmp(n); 
  stack<int> stk; 
  vector<vector<int>> ver(n, vector<int> (n));
  for (int i = 0; i < n; ++i) {//if we start decreasingly
    if (a[i] == 1) {
      if (stk.size()) {
        int top = stk.top();
        stk.pop();
        tmp[top] = 0; 
      }
    } else {
      stk.push(i); 
      tmp[i] = 1; 
    }
    ver[i] = tmp; 
  }
  while (stk.size()) stk.pop();
  queue<int> que; 
  for (int i = 0; i < n; ++i) tmp[i] = 0; 
  vector<vector<int>> ver2(n, vector<int> (n)); 
  for (int i = n - 1; i >= 0; --i) {
    if (a[i] == 1) {
      if (que.size()) {
        int top = que.front();
        que.pop();
        tmp[top] = 0; 
      }
    } else {
      que.push(i);
      tmp[i] = 1; 
    }
    ver2[i] = tmp; 
  }
  int q;
  cin >> q;
  while (q--) {
    int l, r;
    cin >> l >> r;
    --l, --r;
    int ans = 0;
    vector<int> va = ver[r]; 
    Or(va, ver2[l]);  
    for (int i = l; i <= r; ++i) {
      ans += va[i];
    }
    cout << ans << '\n'; 
  }
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18