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Submission #869510

# Submission time Handle Problem Language Result Execution time Memory
869510 2023-11-04T14:45:46 Z tvladm2009 Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 650 ms 59668 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int N = 4000 + 7;
string s[N];
bool vis[N][N];
int dx[] = {+1, -1, 0, 0};
int dy[] = {0, 0, +1, -1};
int n, m, ret = 0;

void bfs(queue<pair<int, int>> &q1, queue<pair<int, int>> &q2, int d) {
  if (q1.empty()) return;
  ret = d;
  while (!q1.empty()) {
    pair<int, int> x = q1.front();
    q1.pop();
    for (int dir = 0; dir < 4; dir++) {
      if (x.first + dx[dir] < 0 || x.first + dx[dir] >= n || x.second + dy[dir] < 0 || x.second + dy[dir] >= m) {
        continue;
      }
      if (vis[x.first + dx[dir]][x.second + dy[dir]] == true || s[x.first + dx[dir]][x.second + dy[dir]] == '.') {
        continue;
      }
      vis[x.first + dx[dir]][x.second + dy[dir]] = 1;
      if (s[x.first + dx[dir]][x.second + dy[dir]] != s[x.first][x.second]) {
        q2.push({x.first + dx[dir], x.second + dy[dir]});
      } else {
        q1.push({x.first + dx[dir], x.second + dy[dir]});
      }
    }
  }
  bfs(q2, q1, d + 1);
}

int main() {
#ifdef ONPC
  freopen("input.txt", "r", stdin);
#endif // ONPC
#ifndef ONPC
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#endif // ONPC

  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    cin >> s[i];
  }
  queue<pair<int, int>> q1, q2;
  q1.push({0, 0});
  vis[0][0] = 1;
  bfs(q1, q2, 1);
  cout << ret << "\n";
  return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 2908 KB Output is correct
2 Correct 0 ms 604 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 5 ms 2908 KB Output is correct
5 Correct 2 ms 1712 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 844 KB Output is correct
9 Correct 1 ms 860 KB Output is correct
10 Correct 2 ms 1624 KB Output is correct
11 Correct 2 ms 1368 KB Output is correct
12 Correct 4 ms 1884 KB Output is correct
13 Correct 2 ms 1884 KB Output is correct
14 Correct 2 ms 1884 KB Output is correct
15 Correct 10 ms 2908 KB Output is correct
16 Correct 9 ms 2852 KB Output is correct
17 Correct 7 ms 2732 KB Output is correct
18 Correct 5 ms 2904 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 15444 KB Output is correct
2 Correct 32 ms 8664 KB Output is correct
3 Correct 150 ms 49492 KB Output is correct
4 Correct 38 ms 15560 KB Output is correct
5 Correct 109 ms 30844 KB Output is correct
6 Correct 604 ms 59596 KB Output is correct
7 Correct 7 ms 16216 KB Output is correct
8 Correct 9 ms 15708 KB Output is correct
9 Correct 1 ms 600 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 7 ms 15932 KB Output is correct
12 Correct 1 ms 1116 KB Output is correct
13 Correct 31 ms 8480 KB Output is correct
14 Correct 20 ms 5988 KB Output is correct
15 Correct 11 ms 6492 KB Output is correct
16 Correct 16 ms 3420 KB Output is correct
17 Correct 80 ms 16728 KB Output is correct
18 Correct 43 ms 16544 KB Output is correct
19 Correct 37 ms 15440 KB Output is correct
20 Correct 36 ms 14416 KB Output is correct
21 Correct 90 ms 31824 KB Output is correct
22 Correct 113 ms 30788 KB Output is correct
23 Correct 168 ms 26344 KB Output is correct
24 Correct 89 ms 31312 KB Output is correct
25 Correct 239 ms 49588 KB Output is correct
26 Correct 305 ms 39528 KB Output is correct
27 Correct 427 ms 51348 KB Output is correct
28 Correct 650 ms 59668 KB Output is correct
29 Correct 577 ms 58064 KB Output is correct
30 Correct 491 ms 56372 KB Output is correct
31 Correct 441 ms 34712 KB Output is correct
32 Correct 339 ms 50076 KB Output is correct