#include <iostream>
#include <vector>
#include <queue>
#define pii pair<int, int>
using namespace std;
int N, S;
int mR, mC, dR, dC;
char grid[801][801];
int minHiveDist[801][801], minBearDist[801][801];
const int dx[4] = { -1, 1, 0, 0 };
const int dy[4] = { 0, 0, -1, 1 };
bool isValid(int r, int c) { return 0 <= r && r < N && 0 <= c && c < N; }
vector<vector<bool>> visited;
void bfs(vector<pii> initialCoords) {
queue<pair<pii, int>> q;
visited.clear(); visited.resize(N, vector<bool>(N));
for (pii p : initialCoords) {
q.push({ p, 0 }); visited[p.first][p.second] = true;
}
while (!q.empty()) {
pii loc = q.front().first; int dist = q.front().second; q.pop();
minHiveDist[loc.first][loc.second] = dist;
for (int i = 0; i < 4; i++) {
int r = loc.first + dx[i], c = loc.second + dy[i];
if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T') {
visited[r][c] = true;
q.push({ {r, c}, dist + 1 });
}
}
}
}
void bfs2(int startR, int startC, int wait) {
visited.clear(); visited.resize(N, vector<bool>(N));
queue<pair<pii, int>> q; q.push({ {startR, startC}, 0 });
visited[startR][startC] = true;
while (!q.empty()) {
pii loc = q.front().first; int dist = q.front().second; q.pop();
minBearDist[loc.first][loc.second] = dist;
for (int i = 0; i < 4; i++) {
int r = loc.first + dx[i], c = loc.second + dy[i];
if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T') {
if ((dist + 1) / S + wait < minHiveDist[r][c]) {
visited[r][c] = true;
q.push({ {r, c}, dist + 1 });
}
}
}
}
}
bool works(int wait) {
if ((long) wait * S >= minHiveDist[mR][mC]) return false;
bfs2(mR, mC, wait);
return visited[dR][dC];
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> S;
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
cin >> grid[i][j];
vector<pii> hives;
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
if (grid[i][j] == 'H') hives.push_back({ i, j });
if (grid[i][j] == 'M') { mR = i; mC = j; }
if (grid[i][j] == 'D') { dR = i; dC = j; }
}
}
bfs(hives); minHiveDist[dR][dC] = (int)1e9;
int low = 0, high = N * N;
while (low < high) {
int mid = (low + high + 1) / 2;
if (works(mid)) low = mid;
else high = mid - 1;
} cout << (works(low) ? low : low - 1) << endl;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
340 KB |
Output is correct |
| 2 |
Correct |
1 ms |
340 KB |
Output is correct |
| 3 |
Correct |
0 ms |
340 KB |
Output is correct |
| 4 |
Correct |
0 ms |
340 KB |
Output is correct |
| 5 |
Correct |
0 ms |
340 KB |
Output is correct |
| 6 |
Correct |
0 ms |
340 KB |
Output is correct |
| 7 |
Incorrect |
34 ms |
5304 KB |
Output isn't correct |
| 8 |
Correct |
1 ms |
340 KB |
Output is correct |
| 9 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 10 |
Correct |
0 ms |
340 KB |
Output is correct |
| 11 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
| 12 |
Incorrect |
1 ms |
724 KB |
Output isn't correct |
| 13 |
Correct |
1 ms |
596 KB |
Output is correct |
| 14 |
Correct |
1 ms |
596 KB |
Output is correct |
| 15 |
Correct |
0 ms |
340 KB |
Output is correct |
| 16 |
Incorrect |
1 ms |
468 KB |
Output isn't correct |
| 17 |
Correct |
0 ms |
340 KB |
Output is correct |
| 18 |
Incorrect |
1 ms |
468 KB |
Output isn't correct |
| 19 |
Correct |
0 ms |
468 KB |
Output is correct |
| 20 |
Incorrect |
0 ms |
468 KB |
Output isn't correct |
| 21 |
Correct |
1 ms |
468 KB |
Output is correct |
| 22 |
Incorrect |
1 ms |
596 KB |
Output isn't correct |
| 23 |
Correct |
1 ms |
468 KB |
Output is correct |
| 24 |
Incorrect |
1 ms |
596 KB |
Output isn't correct |
| 25 |
Correct |
1 ms |
596 KB |
Output is correct |
| 26 |
Incorrect |
1 ms |
724 KB |
Output isn't correct |
| 27 |
Correct |
1 ms |
596 KB |
Output is correct |
| 28 |
Incorrect |
1 ms |
724 KB |
Output isn't correct |
| 29 |
Correct |
1 ms |
596 KB |
Output is correct |
| 30 |
Incorrect |
1 ms |
724 KB |
Output isn't correct |
| 31 |
Correct |
1 ms |
596 KB |
Output is correct |
| 32 |
Incorrect |
1 ms |
852 KB |
Output isn't correct |
| 33 |
Correct |
4 ms |
2024 KB |
Output is correct |
| 34 |
Incorrect |
9 ms |
2772 KB |
Output isn't correct |
| 35 |
Incorrect |
6 ms |
2776 KB |
Output isn't correct |
| 36 |
Correct |
6 ms |
2228 KB |
Output is correct |
| 37 |
Incorrect |
10 ms |
3156 KB |
Output isn't correct |
| 38 |
Incorrect |
13 ms |
3108 KB |
Output isn't correct |
| 39 |
Correct |
7 ms |
2388 KB |
Output is correct |
| 40 |
Incorrect |
10 ms |
3536 KB |
Output isn't correct |
| 41 |
Incorrect |
9 ms |
3540 KB |
Output isn't correct |
| 42 |
Correct |
8 ms |
2644 KB |
Output is correct |
| 43 |
Incorrect |
12 ms |
3856 KB |
Output isn't correct |
| 44 |
Incorrect |
10 ms |
3840 KB |
Output isn't correct |
| 45 |
Correct |
9 ms |
2900 KB |
Output is correct |
| 46 |
Incorrect |
23 ms |
4276 KB |
Output isn't correct |
| 47 |
Incorrect |
12 ms |
4192 KB |
Output isn't correct |
| 48 |
Correct |
11 ms |
3216 KB |
Output is correct |
| 49 |
Incorrect |
26 ms |
4544 KB |
Output isn't correct |
| 50 |
Incorrect |
15 ms |
4532 KB |
Output isn't correct |
| 51 |
Correct |
12 ms |
3404 KB |
Output is correct |
| 52 |
Incorrect |
24 ms |
4948 KB |
Output isn't correct |
| 53 |
Incorrect |
17 ms |
5012 KB |
Output isn't correct |
| 54 |
Correct |
15 ms |
3704 KB |
Output is correct |
| 55 |
Incorrect |
41 ms |
5332 KB |
Output isn't correct |
| 56 |
Incorrect |
25 ms |
5356 KB |
Output isn't correct |
| 57 |
Correct |
16 ms |
3960 KB |
Output is correct |
| 58 |
Incorrect |
43 ms |
5620 KB |
Output isn't correct |
| 59 |
Incorrect |
23 ms |
5712 KB |
Output isn't correct |
| 60 |
Correct |
18 ms |
4180 KB |
Output is correct |
| 61 |
Incorrect |
48 ms |
5972 KB |
Output isn't correct |
| 62 |
Incorrect |
26 ms |
6096 KB |
Output isn't correct |
| 63 |
Correct |
90 ms |
6080 KB |
Output is correct |
| 64 |
Incorrect |
51 ms |
6088 KB |
Output isn't correct |
| 65 |
Correct |
124 ms |
6088 KB |
Output is correct |
| 66 |
Correct |
113 ms |
6084 KB |
Output is correct |
| 67 |
Correct |
97 ms |
5984 KB |
Output is correct |
| 68 |
Correct |
35 ms |
6072 KB |
Output is correct |
| 69 |
Incorrect |
31 ms |
6152 KB |
Output isn't correct |
| 70 |
Correct |
36 ms |
6076 KB |
Output is correct |
| 71 |
Correct |
32 ms |
6132 KB |
Output is correct |
| 72 |
Incorrect |
32 ms |
6076 KB |
Output isn't correct |
| 73 |
Incorrect |
26 ms |
6476 KB |
Output isn't correct |
| 74 |
Incorrect |
33 ms |
6456 KB |
Output isn't correct |
| 75 |
Incorrect |
34 ms |
6500 KB |
Output isn't correct |
| 76 |
Incorrect |
32 ms |
6524 KB |
Output isn't correct |
| 77 |
Incorrect |
39 ms |
6532 KB |
Output isn't correct |
| 78 |
Correct |
50 ms |
5168 KB |
Output is correct |
| 79 |
Incorrect |
34 ms |
6608 KB |
Output isn't correct |
| 80 |
Incorrect |
49 ms |
5076 KB |
Output isn't correct |
| 81 |
Correct |
41 ms |
5044 KB |
Output is correct |
| 82 |
Incorrect |
42 ms |
5176 KB |
Output isn't correct |
| 83 |
Correct |
51 ms |
5104 KB |
Output is correct |
| 84 |
Incorrect |
33 ms |
6348 KB |
Output isn't correct |
| 85 |
Incorrect |
39 ms |
5172 KB |
Output isn't correct |
| 86 |
Correct |
51 ms |
5124 KB |
Output is correct |
| 87 |
Incorrect |
40 ms |
5160 KB |
Output isn't correct |
| 88 |
Correct |
51 ms |
5120 KB |
Output is correct |
| 89 |
Incorrect |
33 ms |
6280 KB |
Output isn't correct |
| 90 |
Incorrect |
34 ms |
5204 KB |
Output isn't correct |
| 91 |
Incorrect |
36 ms |
6320 KB |
Output isn't correct |
| 92 |
Correct |
45 ms |
5204 KB |
Output is correct |
