Submission #820149

#	Time	Username	Problem	Language	Result	Execution time	Memory
820149		WLZ	Quality Of Living (IOI10_quality)	C++17	100 / 100	2566 ms	175584 KiB

quality

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

int R, C, H, W;
int Q[3001][3001];

bool check(int k) {
  vector< vector<int> > pre(R + 1, vector<int>(C + 1, 0));
  for (int i = 0; i < R; i++) for (int j = 0; j < C; j++) if (Q[i][j] <= k) pre[i + 1][j + 1] = 1;
  for (int i = 1; i <= R; i++) for (int j = 1; j <= C; j++) pre[i][j] += pre[i - 1][j] + pre[i][j - 1] - pre[i - 1][j - 1];
  for (int i = H; i <= R; i++) {
    for (int j = W; j <= C; j++) {
      if (pre[i][j] - pre[i - H][j] - pre[i][j - W] + pre[i - H][j - W] >= (H * W + 1) / 2) return true;
    }
  }
  return false;
}

int rectangle(int _R, int _C, int _H, int _W, int _Q[3001][3001]) {
  R = _R, C = _C, H = _H, W = _W;
  for (int i = 0; i < R; i++) for (int j = 0; j < C; j++) Q[i][j] = _Q[i][j];

  int lo = 1, hi = R * C;
  while (lo < hi) {
    //cerr << lo << endl;
    int mid = (lo + hi) / 2;
    if (check(mid)) hi = mid;
    else lo = mid + 1;
  }
  return lo;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20