Submission #1192876

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192876		LucaLucaM	Dango Maker (JOI18_dango_maker)	C++20	0 / 100	106 ms	211856 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];

std::vector<int> g[NMAX * NMAX];

bool vis[NMAX * NMAX];
int l[NMAX], r[NMAX];

bool cupleaza(int u) {
  vis[u] = true;
  for (const auto &v : g[u]) {
    if (r[v] == -1) {
      r[v] = u;
      l[u] = v;
      return true;
    }
  }
  for (const auto &v : g[u]) {
    if (!vis[r[v]] && cupleaza(r[v])) {
      l[u] = v;
      r[v] = u;
      return true;
    }
  }

  return false;
}

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;

  int answer = 0;

  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 < 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') {
        vertl.push_back(i * m + j);
        vertical[i][j] = vertical[i][j + 1] = vertical[i][j + 2] = i * m + j;
      }
    }
  }

  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') {
        vertr.push_back(i * m + j);
        horizontal[i][j] = horizontal[i + 1][j] = horizontal[i + 2][j] = i * m + j;
      }
    }
  }

  for (int i = 0; i + 2 < n; i++) {
    for (int j = 0; j + 2 < 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();
    g[x].push_back(y);
  }
  
  std::vector<bool> atinge((int) vertr.size(), false);

  for (int i = 0; i < (int) vertl.size(); i++) {
    if (g[vertl[i]].empty()) {
      answer++;
    } else {
      for (const auto &j : g[vertl[i]]) {
        atinge[j] = true;
      }
    }
  }

  for (int i = 0; i < (int) vertr.size(); i++) {
    if (!atinge[i]) {
      answer++;
    }
  }
  
  bool repeat = true;

  for (int i = 0; i < (int) vertl.size(); i++) {
    l[i] = -1;
  }
  for (int i = 0; i < (int) vertr.size(); i++) {
    r[i] = -1;
  }

  while (repeat) {
    repeat = false;
    for (int i = 0; i < (int) vertl.size(); i++) {
      vis[i] = false;
    }

    for (int i = 0; i < (int) vertl.size(); i++) {
      if (l[i] == -1 && cupleaza(i)) {
        answer++;
        repeat = true;
      }
    }
  }

  std::cout << answer;

  return 0;
}

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