Submission #996941

#	Time	Username	Problem	Language	Result	Execution time	Memory
996941		MilosMilutinovic	Soccer Stadium (IOI23_soccer)	C++17	30 / 100	4596 ms	11664 KiB

soccer

#include "soccer.h"
#include <bits/stdc++.h>

using namespace std;

const int MAX = 2005;

int n, a[MAX][MAX];
int L[MAX][MAX];
int R[MAX][MAX];
int go[MAX][MAX];
int res;
map<array<int, 5>, bool> was;

void rec(int xl, int xr, int yl, int yr, int cur) {
  if (was[{xl, xr, yl, yr, cur}]) {
    return;
  }
  res = max(res, cur);
  was[{xl, xr, yl, yr}] = true;
  if (xl > 0) {
    // up
    int ptr = yl;
    while (ptr <= yr) {
      if (a[xl - 1][ptr] == 1) {
        ptr = go[xl - 1][ptr];
        continue;
      }
      int t = min(yr, R[xl - 1][ptr]);
      rec(xl - 1, xr, ptr, t, cur + t - ptr + 1);
      ptr = R[xl - 1][ptr] + 1;
    }
  }
  if (xr + 1 < n) {
    // down
    int ptr = yl;
    while (ptr <= yr) {
      if (a[xr + 1][ptr] == 1) {
        ptr = go[xr + 1][ptr];
        continue;
      }
      int t = min(yr, R[xr + 1][ptr]);
      rec(xl, xr + 1, ptr, t, cur + t - ptr + 1);
      ptr = R[xr + 1][ptr] + 1;
    }
  }
}

int biggest_stadium(int N, vector<vector<int>> F) {
  n = N;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      a[i][j] = F[i][j];
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      if (a[i][j] == 1) {
        continue;
      }
      int p = j;
      while (p + 1 < n && a[i][p + 1] == 0) {
        p += 1;
      }
      for (int k = j; k <= p; k++) {
        L[i][k] = j;
        R[i][k] = p;
      }
      j = p;
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = n - 1; j >= 0; j--) {
      if (a[i][j] == 1) {
        go[i][j] = (j == n - 1 ? n : go[i][j + 1]);
      } else {
        go[i][j] = j;
      }
    }
  }
  res = 0;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      if (a[i][j] == 1) {
        continue;
      }
      if (j == 0 || a[i][j - 1] == 1) {
        rec(i, i, j, R[i][j], R[i][j] - j + 1);
      }
    }
  }
  return res;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 6
• Subtask 2: 8 / 8
• Subtask 3: 22 / 22
• Subtask 4: 0 / 18
• Subtask 5: 0 / 16
• Subtask 6: 0 / 30