Submission #814574

#	Time	Username	Problem	Language	Result	Execution time	Memory
814574		devariaota	Tracks in the Snow (BOI13_tracks)	C++17	34.38 / 100	2094 ms	78820 KiB

tracks

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

int h, w, total;
int meadow[4005][4005];
bool vis[4005][4005];
// vector<pair<int, int>> dir = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int dir[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};

int main() {
  cin >> h >> w;
  char in;
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      cin >> in;
      if (in == '.') {
        meadow[i][j] = -1;
      } else if (in == 'R') {
        meadow[i][j] = 1;
        total++;
      }
      else {
        meadow[i][j] = 0;
        total++;
      }
    }
  }

  // for (int i = 1; i <= h; i++) {
  //   for (int j = 1; j <= w; j++) {
  //     cout << meadow[i][j] << "	";
  //   }
  //   cout << endl;
  // }
  int ans = 0;

  while (true) {
    queue<pair<int, int>> q;
    memset(vis, 0, sizeof(vis));

    q.push({1, 1});
    vis[1][1] = 1;
    int row, col, count = 1;
    int top = meadow[1][1];
    meadow[1][1] += 1;
    meadow[1][1] %= 2;
    ans++;

    while (!q.empty()) {
      row = q.front().first;
      col = q.front().second;
      q.pop();

      for (int i = 0; i < 4; i++) {
        if (row + dir[i][0] > 0 and row + dir[i][0] <= h and col + dir[i][1] > 0 and col + dir[i][1] <= w and !vis[row+dir[i][0]][col+dir[i][1]] and meadow[row+dir[i][0]][col+dir[i][1]] == top) {
          q.push({row+dir[i][0], col+dir[i][1]});
          meadow[row+dir[i][0]][col+dir[i][1]] += 1;
          meadow[row+dir[i][0]][col+dir[i][1]] %= 2;
          vis[row+dir[i][0]][col+dir[i][1]] = 1;
          count++;
        }
      }
    }

    // for (int i = 1; i <= h; i++) {
    //   for (int j = 1; j <= w; j++) {
    //     cout << meadow[i][j] << "	";
    //   }
    //   cout << endl;
    // }
    // cout << count << " " << total << endl;
    // cout << endl;

    // break;



    if (count == total) {
      cout << ans << endl;
      return 0;
    }
  }
}

• Subtask 1: 30 / 30
• Subtask 2: 4.375 / 70