#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll
const int mxN = 805;
int N, S;
char grid[mxN][mxN];
int dist[mxN][mxN];
int mecho_dist[mxN][mxN];
pair<int, int> start, finish;
int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, -1, 0, 1};
bool check(int seconds) {
for(auto &x : mecho_dist) for(auto &y : x) y = INT_MAX;
queue<pair<pair<int, int>, int>> q;
int bees = seconds;
if(bees < dist[start.first][start.second]) {
q.push({make_pair(start.first, start.second), 0});
mecho_dist[start.first][start.second] = 0;
}
unordered_map<int, bool> considered;
while(!q.empty()) {
int x = q.front().first.first, y = q.front().first.second;
int cur = q.front().second;
if(x == finish.first && y == finish.second) return true;
if(cur % S == 0 && cur != 0 && !considered[cur]) {
bees++;
considered[cur] = true;
continue;
}
q.pop();
if(bees >= dist[x][y]) continue;
for(int i = 0; i < 4; i++) {
if(x + dx[i] >= 0 && x + dx[i] < N && y + dy[i] >= 0 && y + dy[i] < N && bees < dist[x + dx[i]][y + dy[i]]
&& mecho_dist[x][y] + 1 < mecho_dist[x + dx[i]][y + dy[i]] && (grid[x + dx[i]][y + dy[i]] == 'G'
|| grid[x + dx[i]][y + dy[i]] == 'D')) {
mecho_dist[x + dx[i]][y + dy[i]] = mecho_dist[x][y] + 1;
q.push({make_pair(x + dx[i], y + dy[i]), cur + 1});
}
}
}
// for(int i = 0; i < N; i++) {
// for(int j = 0; j < N; j++) {
// if(mecho_dist[i][j] == INT_MAX) {
// cout << -1 << " ";
// }else {
// cout << mecho_dist[i][j] << " ";
// }
// }
// cout << "\n";
// }
return false;
}
int bin_search() {
int lo = 0, hi = 2 * N * N;
while(lo < hi) {
int mid = (lo + hi + 1) / 2;
if(check(mid)) {
lo = mid;
}else {
hi = mid - 1;
}
}
return lo;
}
void preprocess() {
for(auto &x : dist) for(auto &y : x) y = INT_MAX;
queue<pair<int, int>> q;
for(int i = 0; i < N; i++) {
for(int j = 0; j < N; j++) {
if(grid[i][j] == 'H') {
q.push({i, j});
dist[i][j] = 0;
}
}
}
while(!q.empty()) {
int x = q.front().first, y = q.front().second;
q.pop();
for(int i = 0; i < 4; i++) {
if(x + dx[i] >= 0 && x + dx[i] < N && y + dy[i] >= 0 && y + dy[i] < N && dist[x][y] + 1 < dist[x + dx[i]][y + dy[i]]
&& grid[x + dx[i]][y + dy[i]] == 'G') {
q.push({x + dx[i], y + dy[i]});
dist[x + dx[i]][y + dy[i]] = dist[x][y] + 1;
}
}
}
dist[finish.first][finish.second] = INT_MAX;
}
void solve() {
cin >> N >> S;
for(int i = 0; i < N; i++) {
for(int j = 0; j < N; j++) {
cin >> grid[i][j];
if(grid[i][j] == 'M') {
start.first = i, start.second = j;
grid[i][j] = 'G';
}else if(grid[i][j] == 'D') {
finish.first = i, finish.second = j;
}
}
}
preprocess();
int ans;
ans = bin_search();
if(!check(0)) {
ans = -1;
}
cout << ans << "\n";
}
int32_t main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int T = 1;
// cin >> T;
for(int i = 1; i <= T; ++i) {
solve();
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
10444 KB |
Output is correct |
2 |
Correct |
7 ms |
10444 KB |
Output is correct |
3 |
Correct |
7 ms |
10444 KB |
Output is correct |
4 |
Correct |
6 ms |
10444 KB |
Output is correct |
5 |
Correct |
7 ms |
10444 KB |
Output is correct |
6 |
Correct |
9 ms |
10460 KB |
Output is correct |
7 |
Correct |
121 ms |
11204 KB |
Output is correct |
8 |
Correct |
9 ms |
10444 KB |
Output is correct |
9 |
Correct |
7 ms |
10484 KB |
Output is correct |
10 |
Correct |
9 ms |
10444 KB |
Output is correct |
11 |
Correct |
7 ms |
10444 KB |
Output is correct |
12 |
Correct |
8 ms |
10516 KB |
Output is correct |
13 |
Correct |
9 ms |
10444 KB |
Output is correct |
14 |
Correct |
9 ms |
10444 KB |
Output is correct |
15 |
Correct |
8 ms |
10436 KB |
Output is correct |
16 |
Correct |
9 ms |
10444 KB |
Output is correct |
17 |
Correct |
7 ms |
10444 KB |
Output is correct |
18 |
Correct |
7 ms |
10488 KB |
Output is correct |
19 |
Correct |
8 ms |
10444 KB |
Output is correct |
20 |
Correct |
8 ms |
10444 KB |
Output is correct |
21 |
Correct |
7 ms |
10444 KB |
Output is correct |
22 |
Correct |
11 ms |
10444 KB |
Output is correct |
23 |
Correct |
9 ms |
10480 KB |
Output is correct |
24 |
Correct |
9 ms |
10444 KB |
Output is correct |
25 |
Correct |
10 ms |
10460 KB |
Output is correct |
26 |
Correct |
12 ms |
10520 KB |
Output is correct |
27 |
Correct |
8 ms |
10444 KB |
Output is correct |
28 |
Correct |
8 ms |
10444 KB |
Output is correct |
29 |
Correct |
12 ms |
10420 KB |
Output is correct |
30 |
Correct |
9 ms |
10444 KB |
Output is correct |
31 |
Correct |
8 ms |
10444 KB |
Output is correct |
32 |
Correct |
9 ms |
10444 KB |
Output is correct |
33 |
Correct |
12 ms |
10828 KB |
Output is correct |
34 |
Correct |
12 ms |
10700 KB |
Output is correct |
35 |
Correct |
40 ms |
10740 KB |
Output is correct |
36 |
Correct |
15 ms |
10796 KB |
Output is correct |
37 |
Correct |
15 ms |
10788 KB |
Output is correct |
38 |
Correct |
51 ms |
10800 KB |
Output is correct |
39 |
Correct |
16 ms |
10896 KB |
Output is correct |
40 |
Correct |
15 ms |
10896 KB |
Output is correct |
41 |
Correct |
54 ms |
10828 KB |
Output is correct |
42 |
Correct |
15 ms |
10888 KB |
Output is correct |
43 |
Correct |
16 ms |
10828 KB |
Output is correct |
44 |
Correct |
65 ms |
10952 KB |
Output is correct |
45 |
Correct |
17 ms |
10956 KB |
Output is correct |
46 |
Correct |
18 ms |
10976 KB |
Output is correct |
47 |
Correct |
90 ms |
10956 KB |
Output is correct |
48 |
Correct |
18 ms |
11084 KB |
Output is correct |
49 |
Correct |
23 ms |
11144 KB |
Output is correct |
50 |
Correct |
97 ms |
11008 KB |
Output is correct |
51 |
Correct |
26 ms |
10956 KB |
Output is correct |
52 |
Correct |
20 ms |
10980 KB |
Output is correct |
53 |
Correct |
120 ms |
11056 KB |
Output is correct |
54 |
Correct |
21 ms |
11084 KB |
Output is correct |
55 |
Correct |
23 ms |
11096 KB |
Output is correct |
56 |
Correct |
142 ms |
11092 KB |
Output is correct |
57 |
Correct |
24 ms |
11212 KB |
Output is correct |
58 |
Correct |
25 ms |
11040 KB |
Output is correct |
59 |
Correct |
167 ms |
11136 KB |
Output is correct |
60 |
Correct |
24 ms |
11092 KB |
Output is correct |
61 |
Correct |
26 ms |
11096 KB |
Output is correct |
62 |
Correct |
196 ms |
11108 KB |
Output is correct |
63 |
Correct |
144 ms |
11332 KB |
Output is correct |
64 |
Correct |
230 ms |
11052 KB |
Output is correct |
65 |
Correct |
181 ms |
11096 KB |
Output is correct |
66 |
Correct |
156 ms |
11076 KB |
Output is correct |
67 |
Correct |
153 ms |
11328 KB |
Output is correct |
68 |
Correct |
63 ms |
11148 KB |
Output is correct |
69 |
Correct |
58 ms |
11144 KB |
Output is correct |
70 |
Correct |
56 ms |
11152 KB |
Output is correct |
71 |
Correct |
52 ms |
11192 KB |
Output is correct |
72 |
Correct |
39 ms |
11196 KB |
Output is correct |
73 |
Correct |
46 ms |
11568 KB |
Output is correct |
74 |
Correct |
87 ms |
11644 KB |
Output is correct |
75 |
Correct |
124 ms |
11572 KB |
Output is correct |
76 |
Correct |
81 ms |
11592 KB |
Output is correct |
77 |
Correct |
90 ms |
11588 KB |
Output is correct |
78 |
Correct |
98 ms |
11576 KB |
Output is correct |
79 |
Correct |
77 ms |
11520 KB |
Output is correct |
80 |
Correct |
74 ms |
11580 KB |
Output is correct |
81 |
Correct |
82 ms |
11588 KB |
Output is correct |
82 |
Correct |
74 ms |
11476 KB |
Output is correct |
83 |
Correct |
108 ms |
11396 KB |
Output is correct |
84 |
Correct |
117 ms |
11468 KB |
Output is correct |
85 |
Correct |
115 ms |
11560 KB |
Output is correct |
86 |
Correct |
112 ms |
11444 KB |
Output is correct |
87 |
Correct |
108 ms |
11468 KB |
Output is correct |
88 |
Correct |
109 ms |
11404 KB |
Output is correct |
89 |
Correct |
133 ms |
11340 KB |
Output is correct |
90 |
Correct |
134 ms |
11328 KB |
Output is correct |
91 |
Correct |
119 ms |
11340 KB |
Output is correct |
92 |
Correct |
112 ms |
11396 KB |
Output is correct |