Submission #264473

#	Time	Username	Problem	Language	Result	Execution time	Memory
264473		Bruteforceman	Rectangles (IOI19_rect)	C++14	72 / 100	5090 ms	637696 KiB

rect

#include "bits/stdc++.h"
#include "rect.h"
using namespace std;
const int maxn = 2505;
struct rect {
  int i, j;
  int l, r;
  rect (int i, int j, int l, int r) : i(i), j(j), l(l), r(r) {}
  rect () {}
};
vector <pair <int, int>> ver[maxn][maxn], hor[maxn][maxn];

vector <rect> getLines(vector<std::vector<int>> a) {
  int n = a.size();
  int m = a.front().size();
  vector <int> v[m];
  vector <rect> vert;
  for(int i = 0; i < n; i++) {
    set <int> last;
    vector <int> arr (n, -1);
    for(int j = 0; j < m; j++) {
      set <int> aux;
      for(int k = int(v[j].size()) - 1; k >= 0; k--) {
        aux.insert(v[j][k]);
        if(a[v[j][k]][j] >= a[i][j]) break;
      }
      while(!v[j].empty() && a[v[j].back()][j] <= a[i][j]) {
        v[j].pop_back();
      }
      v[j].push_back(i);
      for(int k : last) {
        if(aux.find(k) == aux.end()) {
          if(k < i - 1) vert.emplace_back(k, i, arr[k], j - 1);
          arr[k] = -1;
        }
      }
      for(int k : aux) {
        if(arr[k] == -1) arr[k] = j;
      }
      last = aux;
    }
    for(int k : last) {
      if(k < i - 1) vert.emplace_back(k, i, arr[k], m - 1);
    }
  }
	return vert;
}
vector <vector <int>> rotate(vector <vector <int>> a) {
  int n = a.size();
  int m = a.front().size();
  vector <vector <int>> b (m, vector <int> (n, 0));
  for(int i = 0; i < m; i++) {
    for(int j = 0; j < n; j++) {
      b[i][j] = a[j][i];
    }
  }
  return b;
}
/*
0 2 1 2
2 4 0 1
1 4 4 4
*/
long long solve(int i, int j) {
  long long ans = 0;
  for(auto x : ver[i][j]) {
    for(auto y : hor[i][j]) {
      if(y.first >= x.first && y.second <= x.second) ++ans;
    }
  }
  /* for(auto x : hor[i][j]) {
    cout << x.first << " " << x.second << endl;
  }
  cout << i << " " << j << " " << ans << endl;
  */
  return ans;
}
long long count_rectangles(vector <vector <int>> a) {
  auto h = getLines(a);
  auto v = getLines(rotate(a));
  int n = a.size();
  int m = a.front().size();
  for(auto &x : v) {
    int aux = x.l;
    x.l = max(0, x.l - 1);
    x.r = min(n - 1, x.r + 1);
    for(int i = x.l; i <= x.r; i++) {
      ver[i][x.j].emplace_back(x.l, x.i);
      // cout << x.j << " " << i << " " << x.i << " " << x.l << endl;
    }
    // cout << x.i << " " << x.j << " " << x.l << " " << x.r << endl;
  }
  for(auto &x : h) {
    int aux = x.l;
    x.l = max(0, x.l - 1);
    x.r = min(m - 1, x.r + 1);
    for(int i = x.l; i <= x.r; i++) {
      hor[x.j][i].emplace_back(x.i, x.l);
    }
  }
  long long ans = 0;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < m; j++) {
      ans += solve(i, j);
    }
  }
  return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:84:9: warning: unused variable 'aux' [-Wunused-variable]
   84 |     int aux = x.l;
      |         ^~~
rect.cpp:94:9: warning: unused variable 'aux' [-Wunused-variable]
   94 |     int aux = x.l;
      |         ^~~

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