Submission #264755

#	Time	Username	Problem	Language	Result	Execution time	Memory
264755		Bruteforceman	Rectangles (IOI19_rect)	C++14	72 / 100	5079 ms	753268 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];
int t[maxn];
vector <int> v[maxn];

vector <rect> getLines(vector<vector<int>> &a) {
  int n = a.size();
  int m = a.front().size();
  vector <rect> vert;
  for(int i = 0; i < m; i++) v[i].clear();
  set <int> last, aux;
  vector <int> arr (n);
  for(int i = 0; i < n; i++) {
    last.clear();
    fill(arr.begin(), arr.end(), -1);
    for(int j = 0; j < m; j++) {
      aux.clear();
      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;
}
void 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];
    }
  }
  a = b;
}
void update(int x, int val) {
  x += 1;
  for(int i = x; i < maxn; i += i & (-i)) {
    t[i] += val;
  }
}
int query(int x) {
  x += 1;
  int sum = 0;
  for(int i = x; i > 0; i -= i & (-i)) {
    sum += t[i];
  }
  return sum;
}
long long solve(int i, int j) {
  long long ans = 0;
  auto cmp = [&] (pair <int, int> i, pair <int, int> j) {
    return i.second < j.second;
  };
  sort(hor[i][j].begin(), hor[i][j].end(), cmp);
  sort(ver[i][j].begin(), ver[i][j].end(), cmp);
  int pt = 0;
  for(auto y : ver[i][j]) {
    while(pt < hor[i][j].size() && hor[i][j][pt].second <= y.second) {
      update(hor[i][j][pt].first, 1); 
      ++pt;
    }
    ans += query(2500) - query(y.first - 1);
  }
  for(int y = 0; y < pt; y++) update(hor[i][j][y].first, -1);
  return ans;
}
long long count_rectangles(vector <vector <int>> a) {
  int n = a.size();
  int m = a.front().size();
  auto h = getLines(a);
  rotate(a);
  auto v = getLines(a);
  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);
    }
  }
  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 solve(int, int)':
rect.cpp:86:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |     while(pt < hor[i][j].size() && hor[i][j][pt].second <= y.second) {
      |           ~~~^~~~~~~~~~~~~~~~~~
rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:102:9: warning: unused variable 'aux' [-Wunused-variable]
  102 |     int aux = x.l;
      |         ^~~
rect.cpp:110:9: warning: unused variable 'aux' [-Wunused-variable]
  110 |     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