#include <bits/stdc++.h>
using namespace std;
char t[1024][1024];
char test[1024][1024];
int dist[1024][1024];
int n, s;
class state{
public:
int x,y,cw;
state(int a, int b, int c): x(a), y(b), cw(c) {}
};
void propagateBees(queue<state>& q, int limit){
while(!q.empty() && q.front().cw < limit){
state cur = q.front();
q.pop();
int x = cur.x;
int y = cur.y;
int w = cur.cw+1;
if(x > 1 && (test[x-1][y] == 'G' || test[x-1][y] == 'M') && dist[x-1][y] > w){
dist[x-1][y] = w;
test[x-1][y] = 'H';
q.emplace(x-1, y, w);
}
if(x < n && (test[x+1][y] == 'G' || test[x+1][y] == 'M') && dist[x+1][y] > w){
dist[x+1][y] = w;
test[x+1][y] = 'H';
q.emplace(x+1, y, w);
}
if(y > 1 && (test[x][y-1] == 'G' || test[x][y-1] == 'M') && dist[x][y-1] > w){
dist[x][y-1] = w;
test[x][y-1] = 'H';
q.emplace(x, y-1, w);
}
if(y < n && (test[x][y+1] == 'G' || test[x][y+1] == 'M') && dist[x][y+1] > w){
dist[x][y+1] = w;
test[x][y+1] = 'H';
q.emplace(x, y+1, w);
}
}
}
void propagateMecho(queue<state>& q, int limit){
while(!q.empty() && q.front().cw < limit){
state cur = q.front();
q.pop();
int x = cur.x;
int y = cur.y;
if(test[x][y] != 'M') continue;
int w = cur.cw+1;
if(x > 1 && (test[x-1][y] == 'G' || test[x-1][y] == 'D') && dist[x-1][y] > w){
dist[x-1][y] = w;
test[x-1][y] = 'M';
q.emplace(x-1, y, w);
}
if(x < n && (test[x+1][y] == 'G' || test[x+1][y] == 'D') && dist[x+1][y] > w){
dist[x+1][y] = w;
test[x+1][y] = 'M';
q.emplace(x+1, y, w);
}
if(y > 1 && (test[x][y-1] == 'G' || test[x][y-1] == 'D') && dist[x][y-1] > w){
dist[x][y-1] = w;
test[x][y-1] = 'M';
q.emplace(x, y-1, w);
}
if(y < n && (test[x][y+1] == 'G' || test[x][y+1] == 'D') && dist[x][y+1] > w){
dist[x][y+1] = w;
test[x][y+1] = 'M';
q.emplace(x, y+1, w);
}
}
}
bool escapePossible(int days){
if(days == -1) return true;
queue<state> q, mq;
int dx, dy;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= n; j++){
test[i][j] = t[i][j];
dist[i][j] = 1e9;
if(t[i][j] == 'H'){
q.emplace(i,j,0);
dist[i][j] = 0;
}else if(t[i][j] == 'D'){
dx = i;
dy = j;
}else if(t[i][j] == 'M'){
mq.emplace(i,j,0);
dist[i][j] = 0;
}
}
}
propagateBees(q, days);
int lm = 0;
while(!mq.empty() && !q.empty() && test[dx][dy] != 'M'){
lm += s;
propagateMecho(mq, lm);
if(test[dx][dy] == 'M') return true;
days++;
propagateBees(q, days);
}
return test[dx][dy] == 'M';
}
int main(){
scanf("%d%d",&n,&s);
for(int i = 1; i <= n; i++){
scanf("%s", t[i]+1);
}
int lo = -1;
int hi = n*n;
int mid;
while(lo < hi){
mid = (lo+hi+1)/2;
if(escapePossible(mid)){
lo = mid;
}else{
hi = mid-1;
}
}
printf("%d\n", lo);
return 0;
}
Compilation message
mecho.cpp: In function 'int main()':
mecho.cpp:103:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
103 | scanf("%d%d",&n,&s);
| ~~~~~^~~~~~~~~~~~~~
mecho.cpp:105:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
105 | scanf("%s", t[i]+1);
| ~~~~~^~~~~~~~~~~~~~
mecho.cpp: In function 'bool escapePossible(int)':
mecho.cpp:74:10: warning: 'dy' may be used uninitialized in this function [-Wmaybe-uninitialized]
74 | int dx, dy;
| ^~
mecho.cpp:74:6: warning: 'dx' may be used uninitialized in this function [-Wmaybe-uninitialized]
74 | int dx, dy;
| ^~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
2 |
Correct |
0 ms |
384 KB |
Output is correct |
3 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
4 |
Correct |
0 ms |
384 KB |
Output is correct |
5 |
Correct |
1 ms |
384 KB |
Output is correct |
6 |
Correct |
1 ms |
384 KB |
Output is correct |
7 |
Correct |
304 ms |
5944 KB |
Output is correct |
8 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
9 |
Correct |
1 ms |
384 KB |
Output is correct |
10 |
Correct |
1 ms |
384 KB |
Output is correct |
11 |
Correct |
1 ms |
384 KB |
Output is correct |
12 |
Correct |
2 ms |
640 KB |
Output is correct |
13 |
Incorrect |
1 ms |
640 KB |
Output isn't correct |
14 |
Correct |
2 ms |
636 KB |
Output is correct |
15 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
16 |
Correct |
1 ms |
384 KB |
Output is correct |
17 |
Incorrect |
1 ms |
512 KB |
Output isn't correct |
18 |
Correct |
1 ms |
512 KB |
Output is correct |
19 |
Incorrect |
1 ms |
512 KB |
Output isn't correct |
20 |
Correct |
1 ms |
512 KB |
Output is correct |
21 |
Incorrect |
1 ms |
512 KB |
Output isn't correct |
22 |
Correct |
1 ms |
512 KB |
Output is correct |
23 |
Incorrect |
1 ms |
640 KB |
Output isn't correct |
24 |
Correct |
1 ms |
640 KB |
Output is correct |
25 |
Incorrect |
1 ms |
640 KB |
Output isn't correct |
26 |
Correct |
2 ms |
640 KB |
Output is correct |
27 |
Incorrect |
1 ms |
768 KB |
Output isn't correct |
28 |
Correct |
1 ms |
768 KB |
Output is correct |
29 |
Incorrect |
1 ms |
768 KB |
Output isn't correct |
30 |
Correct |
1 ms |
768 KB |
Output is correct |
31 |
Incorrect |
1 ms |
768 KB |
Output isn't correct |
32 |
Correct |
1 ms |
768 KB |
Output is correct |
33 |
Incorrect |
23 ms |
2560 KB |
Output isn't correct |
34 |
Correct |
25 ms |
2736 KB |
Output is correct |
35 |
Correct |
36 ms |
2560 KB |
Output is correct |
36 |
Incorrect |
35 ms |
2936 KB |
Output isn't correct |
37 |
Correct |
35 ms |
2936 KB |
Output is correct |
38 |
Correct |
53 ms |
2948 KB |
Output is correct |
39 |
Incorrect |
43 ms |
3200 KB |
Output isn't correct |
40 |
Correct |
44 ms |
3200 KB |
Output is correct |
41 |
Correct |
63 ms |
3292 KB |
Output is correct |
42 |
Incorrect |
53 ms |
3584 KB |
Output isn't correct |
43 |
Correct |
54 ms |
3632 KB |
Output is correct |
44 |
Correct |
79 ms |
3584 KB |
Output is correct |
45 |
Incorrect |
73 ms |
3980 KB |
Output isn't correct |
46 |
Correct |
76 ms |
3968 KB |
Output is correct |
47 |
Correct |
102 ms |
4216 KB |
Output is correct |
48 |
Incorrect |
86 ms |
4224 KB |
Output isn't correct |
49 |
Correct |
80 ms |
4224 KB |
Output is correct |
50 |
Correct |
116 ms |
4376 KB |
Output is correct |
51 |
Incorrect |
92 ms |
4728 KB |
Output isn't correct |
52 |
Correct |
95 ms |
4608 KB |
Output is correct |
53 |
Correct |
153 ms |
4608 KB |
Output is correct |
54 |
Incorrect |
107 ms |
4992 KB |
Output isn't correct |
55 |
Correct |
113 ms |
5112 KB |
Output is correct |
56 |
Correct |
170 ms |
5112 KB |
Output is correct |
57 |
Incorrect |
121 ms |
5368 KB |
Output isn't correct |
58 |
Correct |
125 ms |
5368 KB |
Output is correct |
59 |
Correct |
198 ms |
5248 KB |
Output is correct |
60 |
Incorrect |
149 ms |
5632 KB |
Output isn't correct |
61 |
Correct |
144 ms |
5632 KB |
Output is correct |
62 |
Correct |
220 ms |
5652 KB |
Output is correct |
63 |
Correct |
251 ms |
5752 KB |
Output is correct |
64 |
Correct |
282 ms |
5752 KB |
Output is correct |
65 |
Correct |
236 ms |
5632 KB |
Output is correct |
66 |
Correct |
266 ms |
5752 KB |
Output is correct |
67 |
Correct |
252 ms |
5880 KB |
Output is correct |
68 |
Correct |
266 ms |
5880 KB |
Output is correct |
69 |
Correct |
240 ms |
5752 KB |
Output is correct |
70 |
Correct |
243 ms |
5632 KB |
Output is correct |
71 |
Correct |
278 ms |
5752 KB |
Output is correct |
72 |
Incorrect |
305 ms |
5692 KB |
Output isn't correct |
73 |
Incorrect |
367 ms |
6328 KB |
Output isn't correct |
74 |
Correct |
362 ms |
6196 KB |
Output is correct |
75 |
Correct |
396 ms |
6064 KB |
Output is correct |
76 |
Correct |
377 ms |
6052 KB |
Output is correct |
77 |
Correct |
363 ms |
6144 KB |
Output is correct |
78 |
Correct |
334 ms |
6032 KB |
Output is correct |
79 |
Correct |
345 ms |
6144 KB |
Output is correct |
80 |
Correct |
338 ms |
6112 KB |
Output is correct |
81 |
Correct |
326 ms |
6016 KB |
Output is correct |
82 |
Correct |
335 ms |
6144 KB |
Output is correct |
83 |
Correct |
327 ms |
6044 KB |
Output is correct |
84 |
Correct |
342 ms |
5936 KB |
Output is correct |
85 |
Correct |
363 ms |
5944 KB |
Output is correct |
86 |
Correct |
330 ms |
5944 KB |
Output is correct |
87 |
Correct |
324 ms |
5952 KB |
Output is correct |
88 |
Correct |
319 ms |
6008 KB |
Output is correct |
89 |
Correct |
321 ms |
5872 KB |
Output is correct |
90 |
Correct |
321 ms |
5932 KB |
Output is correct |
91 |
Correct |
320 ms |
6000 KB |
Output is correct |
92 |
Correct |
345 ms |
5872 KB |
Output is correct |