Submission #420849

#	Time	Username	Problem	Language	Result	Execution time	Memory
420849		SSRS	Rectangles (IOI19_rect)	C++14	10 / 100	4 ms	844 KiB

rect

#include <bits/stdc++.h>
using namespace std;
long long count_rectangles(vector<vector<int>> a){
  int n = a.size();
  int m = a[0].size();
  if (n < 3){
    return 0;
  }
  assert(n == 3);
  vector<bool> c(m);
  for (int i = 0; i < m; i++){
    c[i] = a[0][i] > a[1][i] && a[2][i] > a[1][i];
  }
  vector<int> S(m + 1);
  S[0] = 0;
  for (int i = 0; i < m; i++){
    S[i + 1] = S[i];
    if (!c[i]){
      S[i + 1]++;
    }
  }
  map<int, vector<int>> mp;
  for (int j = 0; j < m; j++){
    mp[a[1][j]].push_back(j);
  }
  set<int> st = {-1, m};
  set<pair<int, int>> ans;
  for (auto itr = mp.rbegin(); itr != mp.rend(); itr++){
    vector<int> id = (*itr).second;
    for (int i : id){
      if (i > 0 && i < m - 1){
        int L = *prev(st.lower_bound(i)) + 1;
        int R = *st.lower_bound(i);
        if (0 < L && R < m){
          if (S[R] - S[L] == 0){
            ans.insert(make_pair(L, R));
          }
        }
      }
    }
    for (int i : id){
      st.insert(i);
    }  
  }
  return ans.size();
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 22
• Subtask 5: 10 / 10
• Subtask 6: 0 / 13
• Subtask 7: 0 / 28