Submission #1192906

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192906		LucaLucaM	Dango Maker (JOI18_dango_maker)	C++20	13 / 100	1928 ms	560 KiB

dango_maker

#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>

using ll = long long;
#define debug(x) #x << " = " << x << '\n'

const int NMAX = 3000;

char a[NMAX][NMAX];
int vertical[NMAX][NMAX], horizontal[NMAX][NMAX];

int main() {
  #ifdef LOCAL
    freopen("input.txt", "r", stdin);
  #endif
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(0);

  int n, m;
  std::cin >> n >> m;

  for (int i = 0; i < n; i++) {
    std::string s;
    std::cin >> s;
    for (int j = 0; j < m; j++) {
      a[i][j] = s[j];
    }
  }

  std::vector<int> vertl, vertr;
  std::vector<std::pair<int, int>> edges;

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      vertical[i][j] = horizontal[i][j] = -1;
    }
  }

  for (int i = 0; i + 2 < n; i++) {
    for (int j = 0; j < m; j++) {
      if (a[i][j] == 'R' && a[i + 1][j] == 'G' && a[i + 2][j] == 'W') {
        vertl.push_back(i * m + j);
        vertical[i][j] = vertical[i + 1][j] = vertical[i + 2][j] = i * m + j;
      }
    }
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j + 2 < m; j++) {
      if (a[i][j] == 'R' && a[i][j + 1] == 'G' && a[i][j + 2] == 'W') {
        vertr.push_back(i * m + j);
        horizontal[i][j] = horizontal[i][j + 1] = horizontal[i][j + 2] = i * m + j;
      }
    }
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (vertical[i][j] != -1 && horizontal[i][j] != -1) {
        edges.push_back({vertical[i][j], horizontal[i][j]});
      }
    }
  }

  std::sort(vertl.begin(), vertl.end());
  vertl.erase(std::unique(vertl.begin(), vertl.end()), vertl.end());

  std::sort(vertr.begin(), vertr.end());
  vertr.erase(std::unique(vertr.begin(), vertr.end()), vertr.end());

  for (auto &[x, y] : edges) {
    x = std::lower_bound(vertl.begin(), vertl.end(), x) - vertl.begin();
    y = std::lower_bound(vertr.begin(), vertr.end(), y) - vertr.begin();
  }

  int answer = 0;
  
  int L = (int) vertl.size();
  int R = (int) vertr.size();

  for (int mask = 0; mask < (1 << (L + R)); mask++) {
    int st = 0, dr = 0;
    std::vector<std::vector<int>> cnt(n, std::vector<int>(m, 0));

    for (int i = 0; i < L + R; i++) {
      if (mask >> i & 1) {
        if (i < L) {
          int x = vertl[i] / m, y = vertl[i] % m;
          cnt[x][y]++;
          cnt[x + 1][y]++;
          cnt[x + 2][y]++;
        } else {
          int x = vertr[i - L] / m, y = vertr[i - L] % m;
          cnt[x][y]++;
          cnt[x][y + 1]++;
          cnt[x][y + 2]++;
        }
      }
    }

    bool ok = true;
    for (const auto &[x, y] : edges) {
      if (mask >> x & 1) {
        if (mask >> (y + L) & 1) {
          ok = false;
          break;
        }
      }
    }
    
    if (ok) {
      answer = std::max(answer, __builtin_popcount(mask));
    }
  }
  

  std::cout << answer;

  return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 0 / 20
• Subtask 3: 0 / 67