#include <bits/stdc++.h>
#define pb push_back
using namespace std;
const int INF = 1e6;
vector<vector<int>> time_bees;
int max_bees = 0;
void bfs_bees(vector<pair<int, int>>& hives, int n, vector<vector<char>>& map) {
queue<pair<int, int>> q;
for (pair<int, int> h : hives) {
q.push(h);
time_bees[h.first][h.second] = 0;
}
while (!q.empty()) {
pair<int, int> pos = q.front();
q.pop();
int i = pos.first, j = pos.second;
max_bees = max(max_bees, time_bees[i][j]);
if (i > 0 && time_bees[i-1][j] == INF && map[i-1][j] == 'G') {
time_bees[i-1][j] = time_bees[i][j]+1;
q.push({i-1, j});
}
if (i < n-1 && time_bees[i+1][j] == INF && map[i+1][j] == 'G') {
time_bees[i+1][j] = time_bees[i][j]+1;
q.push({i+1, j});
}
if (j > 0 && time_bees[i][j-1] == INF && map[i][j-1] == 'G') {
time_bees[i][j-1] = time_bees[i][j]+1;
q.push({i, j-1});
}
if (j < n-1 && time_bees[i][j+1] == INF && map[i][j+1] == 'G') {
time_bees[i][j+1] = time_bees[i][j]+1;
q.push({i, j+1});
}
}
}
bool CanGetHome(pair<int, int> r, vector<vector<char>>& map, int s, int t, pair<int, int> d) {
int n = (int)map.size();
queue<pair<pair<int, int>, int>> q;
vector<vector<int>> visited(n, vector<int>(n, 0));
visited[r.first][r.second] = 1;
q.push({r, s*t});
while (!q.empty()) {
pair<int, int> pos = q.front().first;
int steps = q.front().second;
q.pop();
int i = pos.first, j = pos.second;
if (pos == d) return true;
if (steps%s == 0) {
if ((steps+s-1)/s >= time_bees[i][j]) continue;
} else if ((steps+s-1)/s > time_bees[i][j]) continue;
if (i > 0 && !visited[i-1][j] && map[i-1][j] == 'G') {
visited[i-1][j] = 1;
q.push({{i-1, j}, steps+1});
}
if (i < n-1 && !visited[i+1][j] && map[i+1][j] == 'G') {
visited[i+1][j] = 1;
q.push({{i+1, j}, steps+1});
}
if (j > 0 && !visited[i][j-1] && map[i][j-1] == 'G') {
visited[i][j-1] = 1;
q.push({{i, j-1}, steps+1});
}
if (j < n-1 && !visited[i][j+1] && map[i][j+1] == 'G') {
visited[i][j+1] = 1;
q.push({{i, j+1}, steps+1});
}
}
return false;
}
int main() {
int n, s;
cin >> n >> s;
vector<vector<char>> map(n, vector<char>(n));
vector<pair<int, int>> hives;
pair<int, int> mecho, home;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < n; ++j) {
cin >> map[i][j];
if (map[i][j] == 'H') hives.pb({i, j});
else if (map[i][j] == 'M') {
mecho = {i, j};
map[i][j] = 'G';
} else if (map[i][j] == 'D') home = {i, j};
}
}
time_bees = vector<vector<int>>(n, vector<int>(n, INF));
bfs_bees(hives, n, map);
map[home.first][home.second] = 'G';
int l = 0, r = max_bees, ans = -1;
while (l <= r) {
int m = (l+r)/2;
if (CanGetHome(mecho, map, s, m, home)) {
l = m+1;
ans = m;
} else r = m-1;
}
cout << ans << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
344 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
68 ms |
6156 KB |
Output is correct |
8 |
Correct |
0 ms |
344 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
600 KB |
Output is correct |
16 |
Correct |
0 ms |
344 KB |
Output is correct |
17 |
Correct |
1 ms |
344 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
1 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
0 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
348 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
1 ms |
348 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
1 ms |
348 KB |
Output is correct |
30 |
Correct |
1 ms |
348 KB |
Output is correct |
31 |
Correct |
1 ms |
344 KB |
Output is correct |
32 |
Correct |
1 ms |
344 KB |
Output is correct |
33 |
Correct |
7 ms |
1532 KB |
Output is correct |
34 |
Correct |
8 ms |
1524 KB |
Output is correct |
35 |
Correct |
15 ms |
1476 KB |
Output is correct |
36 |
Correct |
10 ms |
1760 KB |
Output is correct |
37 |
Correct |
9 ms |
1880 KB |
Output is correct |
38 |
Correct |
19 ms |
1880 KB |
Output is correct |
39 |
Correct |
14 ms |
2276 KB |
Output is correct |
40 |
Correct |
12 ms |
2264 KB |
Output is correct |
41 |
Correct |
24 ms |
2228 KB |
Output is correct |
42 |
Correct |
15 ms |
2684 KB |
Output is correct |
43 |
Correct |
15 ms |
2692 KB |
Output is correct |
44 |
Correct |
31 ms |
2676 KB |
Output is correct |
45 |
Correct |
20 ms |
3212 KB |
Output is correct |
46 |
Correct |
18 ms |
3160 KB |
Output is correct |
47 |
Correct |
40 ms |
3172 KB |
Output is correct |
48 |
Correct |
23 ms |
3904 KB |
Output is correct |
49 |
Correct |
21 ms |
3692 KB |
Output is correct |
50 |
Correct |
58 ms |
3644 KB |
Output is correct |
51 |
Correct |
25 ms |
4188 KB |
Output is correct |
52 |
Correct |
25 ms |
4208 KB |
Output is correct |
53 |
Correct |
56 ms |
4476 KB |
Output is correct |
54 |
Correct |
38 ms |
4840 KB |
Output is correct |
55 |
Correct |
30 ms |
4836 KB |
Output is correct |
56 |
Correct |
71 ms |
4840 KB |
Output is correct |
57 |
Correct |
35 ms |
5464 KB |
Output is correct |
58 |
Correct |
33 ms |
5468 KB |
Output is correct |
59 |
Correct |
77 ms |
5464 KB |
Output is correct |
60 |
Correct |
39 ms |
6180 KB |
Output is correct |
61 |
Correct |
37 ms |
6184 KB |
Output is correct |
62 |
Correct |
87 ms |
6144 KB |
Output is correct |
63 |
Correct |
102 ms |
6180 KB |
Output is correct |
64 |
Correct |
151 ms |
6164 KB |
Output is correct |
65 |
Correct |
145 ms |
6156 KB |
Output is correct |
66 |
Correct |
120 ms |
6312 KB |
Output is correct |
67 |
Correct |
106 ms |
6128 KB |
Output is correct |
68 |
Correct |
55 ms |
6148 KB |
Output is correct |
69 |
Correct |
49 ms |
6164 KB |
Output is correct |
70 |
Correct |
53 ms |
6200 KB |
Output is correct |
71 |
Correct |
46 ms |
6148 KB |
Output is correct |
72 |
Correct |
43 ms |
6160 KB |
Output is correct |
73 |
Correct |
44 ms |
6220 KB |
Output is correct |
74 |
Correct |
55 ms |
6208 KB |
Output is correct |
75 |
Correct |
54 ms |
6168 KB |
Output is correct |
76 |
Correct |
56 ms |
6216 KB |
Output is correct |
77 |
Correct |
62 ms |
6200 KB |
Output is correct |
78 |
Correct |
62 ms |
6176 KB |
Output is correct |
79 |
Correct |
57 ms |
6200 KB |
Output is correct |
80 |
Correct |
56 ms |
6188 KB |
Output is correct |
81 |
Correct |
61 ms |
6224 KB |
Output is correct |
82 |
Correct |
52 ms |
6192 KB |
Output is correct |
83 |
Correct |
66 ms |
6184 KB |
Output is correct |
84 |
Correct |
62 ms |
6184 KB |
Output is correct |
85 |
Correct |
58 ms |
6172 KB |
Output is correct |
86 |
Correct |
64 ms |
6180 KB |
Output is correct |
87 |
Correct |
63 ms |
6192 KB |
Output is correct |
88 |
Correct |
67 ms |
6088 KB |
Output is correct |
89 |
Correct |
71 ms |
6188 KB |
Output is correct |
90 |
Correct |
68 ms |
6172 KB |
Output is correct |
91 |
Correct |
65 ms |
6156 KB |
Output is correct |
92 |
Correct |
66 ms |
6168 KB |
Output is correct |