Submission #886864

#	Time	Username	Problem	Language	Result	Execution time	Memory
886864		NeroZein	Dango Maker (JOI18_dango_maker)	C++17	33 / 100	222 ms	262144 KiB

dango_maker

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

#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif

const int N = 3003;

char c[N][N]; 
int used[N][N];
vector<set<int>> g; 

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      cin >> c[i][j];
    }
  }
  
  int tmp = 0, num = 0;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m - 2; ++j) {
      if (c[i][j] == 'R' && c[i][j + 1] == 'G' && c[i][j + 2] == 'W') {
        tmp++; num++;
        used[i][j] = used[i][j + 1] = used[i][j + 2] = num; 
      }
    }
  }
  
  int original = num; 
  g.resize(original + 1);
  vector<bool> in_que(num + 1);
  for (int i = 0; i < n - 2; ++i) {
    for (int j = 0; j < m; ++j) {
      if (c[i][j] == 'R' && c[i + 1][j] == 'G' && c[i + 2][j] == 'W') {
        num++; 
        g.push_back({});
        for (int k = 0; k < 3; ++k) {
          if (used[i + k][j]) {
            g[num].insert(used[i + k][j]);
            g[used[i + k][j]].insert(num); 
          }
        }          
        if (g[num].size() == 0) {
          tmp++; 
        }
      }
    }
  }
  int ans = tmp; 
  queue<int> que; 
  for (int i = 1; i <= original; ++i) {
    for (int u : g[i]) {
      if (g[u].size() == 1) {
        in_que[i] = true; 
        que.push(i); 
        break; 
      }      
    }
  }
  while (!que.empty()) {
    int v = que.front();
    que.pop(); 
    ans--;
    for (int u : g[v]) {
      g[u].erase(v);
      if (g[u].size() == 0) {
        ans++; 
      } else if (g[u].size() == 1) {
        assert(!g[u].empty()); 
        int z = *g[u].begin();
        if (!in_que[z]) {
          que.push(*g[u].begin());
          assert(z <= original); 
          in_que[z] = true; 
        }
      }
    }
  }
  cout << ans << '\n';
  return 0;
}

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