#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 800;
vector <string> field(MAX_N);
bool bees_visited[MAX_N][MAX_N], mecho_visited[MAX_N][MAX_N];
int mecho_dis[MAX_N][MAX_N], bees_dis[MAX_N][MAX_N];
queue <pair <int, int>> mecho_q, bees_q;
int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
int n, s;
bool valid_sq(int x, int y){
if (x >= 0 && x < n && y >= 0 && y < n && field[x][y] != 'T' && field[x][y] != 'H')
return true;
return false;
}
void update_field(queue <pair <int, int>> &q, int max_steps, bool (&visited)[MAX_N][MAX_N], bool (&visited2)[MAX_N][MAX_N], int (&dis)[MAX_N][MAX_N], bool is_mecho){
while (!q.empty() && dis[q.front().first][q.front().second] != -1){
int x = q.front().first, y = q.front().second;
q.pop();
if (is_mecho && visited2[x][y])
continue;
for (int i = 0; i < 4; i++){
if (valid_sq(x + dx[i], y + dy[i]) && !visited[x+dx[i]][y+dy[i]] && !visited2[x+dx[i]][y+dy[i]]){
q.push({x+dx[i], y+dy[i]});
visited[x+dx[i]][y+dy[i]] = true;
if (dis[x][y] + 1 < max_steps)
dis[x+dx[i]][y+dy[i]] = dis[x][y] + 1;
else
dis[x+dx[i]][y+dy[i]] = -1;
}
}
}
}
int main()
{
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
cin >> n >> s;
for (int i = 0; i < n; i++)
cin >> field[i];
vector <pair <int, int>> hives;
int startx, starty, home_x, home_y;
//find Mecho's position
for (int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
if (field[i][j] == 'M'){
startx = i;
starty = j;
}else if (field[i][j] == 'H'){
hives.push_back({i, j});
}else if (field[i][j] == 'D'){
home_x = i;
home_y = j;
}
}
}
int l = 0, r = 2*n;
while (l <= r){
int eating_time = (l + r) / 2;
memset(bees_visited, false, sizeof(bees_visited));
memset(mecho_visited, false, sizeof(mecho_visited));
memset(bees_dis, 0, sizeof(bees_dis));
memset(mecho_dis, 0, sizeof(mecho_dis));
//simulate
for (auto i : hives){
bees_q.push({i.first, i.second});
bees_visited[i.first][i.second] = true;
}
if (eating_time > 0){
for (int i = 0; i < eating_time; i++){
update_field(bees_q, 1, bees_visited, bees_visited, bees_dis, false);
while (!bees_q.empty() && bees_dis[bees_q.front().first][bees_q.front().second] == -1){
bees_dis[bees_q.front().first][bees_q.front().second] = 0;
bees_q.push({bees_q.front().first, bees_q.front().second});
bees_q.pop();
}
}
}
mecho_q.push({startx, starty});
for (int i = eating_time; i <= n*2-2 && !bees_q.empty() && !mecho_q.empty(); i++){
while (!bees_q.empty() && bees_dis[bees_q.front().first][bees_q.front().second] == -1){
bees_dis[bees_q.front().first][bees_q.front().second] = 0;
bees_q.push({bees_q.front().first, bees_q.front().second});
bees_q.pop();
}while (!mecho_q.empty() && mecho_dis[mecho_q.front().first][mecho_q.front().second] == -1){
mecho_dis[mecho_q.front().first][mecho_q.front().second] = 0;
mecho_q.push({mecho_q.front().first, mecho_q.front().second});
mecho_q.pop();
}
update_field(mecho_q, s, mecho_visited, bees_visited, mecho_dis, true);
if (mecho_visited[home_x][home_y])
break;
update_field(bees_q, 1, bees_visited, bees_visited, bees_dis, false);
}
if (mecho_visited[home_x][home_y])
l = eating_time + 1;
else
r = eating_time - 1;
//empty_queues
while (!bees_q.empty())
bees_q.pop();
while (!mecho_q.empty())
mecho_q.pop();
}
cout << l - 1 << '\n';
}
Compilation message
mecho.cpp: In function 'int main()':
mecho.cpp:95:41: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
95 | if (mecho_visited[home_x][home_y])
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mecho.cpp:95:41: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
6476 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
6476 KB |
Output isn't correct |
| 3 |
Correct |
3 ms |
6476 KB |
Output is correct |
| 4 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 5 |
Correct |
3 ms |
6476 KB |
Output is correct |
| 6 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 7 |
Incorrect |
285 ms |
7444 KB |
Output isn't correct |
| 8 |
Correct |
4 ms |
6476 KB |
Output is correct |
| 9 |
Correct |
4 ms |
6476 KB |
Output is correct |
| 10 |
Correct |
4 ms |
6476 KB |
Output is correct |
| 11 |
Correct |
4 ms |
6476 KB |
Output is correct |
| 12 |
Incorrect |
4 ms |
6472 KB |
Output isn't correct |
| 13 |
Correct |
5 ms |
6588 KB |
Output is correct |
| 14 |
Correct |
5 ms |
6584 KB |
Output is correct |
| 15 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 16 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 17 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 18 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 19 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 20 |
Incorrect |
4 ms |
6576 KB |
Output isn't correct |
| 21 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 22 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 23 |
Incorrect |
4 ms |
6584 KB |
Output isn't correct |
| 24 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 25 |
Incorrect |
5 ms |
6476 KB |
Output isn't correct |
| 26 |
Incorrect |
5 ms |
6476 KB |
Output isn't correct |
| 27 |
Incorrect |
5 ms |
6476 KB |
Output isn't correct |
| 28 |
Incorrect |
6 ms |
6548 KB |
Output isn't correct |
| 29 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 30 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 31 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 32 |
Incorrect |
4 ms |
6476 KB |
Output isn't correct |
| 33 |
Incorrect |
8 ms |
6752 KB |
Output isn't correct |
| 34 |
Incorrect |
8 ms |
6732 KB |
Output isn't correct |
| 35 |
Correct |
32 ms |
6624 KB |
Output is correct |
| 36 |
Incorrect |
8 ms |
6732 KB |
Output isn't correct |
| 37 |
Incorrect |
9 ms |
6732 KB |
Output isn't correct |
| 38 |
Correct |
56 ms |
6776 KB |
Output is correct |
| 39 |
Incorrect |
11 ms |
6776 KB |
Output isn't correct |
| 40 |
Incorrect |
10 ms |
6756 KB |
Output isn't correct |
| 41 |
Correct |
57 ms |
6800 KB |
Output is correct |
| 42 |
Incorrect |
11 ms |
7004 KB |
Output isn't correct |
| 43 |
Incorrect |
12 ms |
7020 KB |
Output isn't correct |
| 44 |
Correct |
66 ms |
7044 KB |
Output is correct |
| 45 |
Incorrect |
16 ms |
6988 KB |
Output isn't correct |
| 46 |
Incorrect |
15 ms |
7064 KB |
Output isn't correct |
| 47 |
Correct |
84 ms |
7084 KB |
Output is correct |
| 48 |
Incorrect |
13 ms |
7148 KB |
Output isn't correct |
| 49 |
Incorrect |
18 ms |
7156 KB |
Output isn't correct |
| 50 |
Correct |
92 ms |
7116 KB |
Output is correct |
| 51 |
Incorrect |
15 ms |
7116 KB |
Output isn't correct |
| 52 |
Incorrect |
16 ms |
7172 KB |
Output isn't correct |
| 53 |
Correct |
117 ms |
7188 KB |
Output is correct |
| 54 |
Incorrect |
16 ms |
7236 KB |
Output isn't correct |
| 55 |
Incorrect |
18 ms |
7256 KB |
Output isn't correct |
| 56 |
Correct |
124 ms |
7252 KB |
Output is correct |
| 57 |
Incorrect |
18 ms |
7244 KB |
Output isn't correct |
| 58 |
Incorrect |
23 ms |
7252 KB |
Output isn't correct |
| 59 |
Correct |
146 ms |
7304 KB |
Output is correct |
| 60 |
Incorrect |
21 ms |
7312 KB |
Output isn't correct |
| 61 |
Incorrect |
26 ms |
7324 KB |
Output isn't correct |
| 62 |
Correct |
172 ms |
7332 KB |
Output is correct |
| 63 |
Incorrect |
246 ms |
7260 KB |
Output isn't correct |
| 64 |
Correct |
186 ms |
7244 KB |
Output is correct |
| 65 |
Correct |
251 ms |
7340 KB |
Output is correct |
| 66 |
Correct |
263 ms |
7332 KB |
Output is correct |
| 67 |
Correct |
237 ms |
7364 KB |
Output is correct |
| 68 |
Correct |
234 ms |
7372 KB |
Output is correct |
| 69 |
Correct |
208 ms |
7360 KB |
Output is correct |
| 70 |
Correct |
235 ms |
7352 KB |
Output is correct |
| 71 |
Correct |
252 ms |
7380 KB |
Output is correct |
| 72 |
Correct |
334 ms |
7372 KB |
Output is correct |
| 73 |
Correct |
248 ms |
7636 KB |
Output is correct |
| 74 |
Correct |
498 ms |
7632 KB |
Output is correct |
| 75 |
Correct |
379 ms |
7624 KB |
Output is correct |
| 76 |
Correct |
517 ms |
7632 KB |
Output is correct |
| 77 |
Correct |
413 ms |
7632 KB |
Output is correct |
| 78 |
Correct |
322 ms |
7600 KB |
Output is correct |
| 79 |
Correct |
329 ms |
7604 KB |
Output is correct |
| 80 |
Correct |
339 ms |
7588 KB |
Output is correct |
| 81 |
Correct |
362 ms |
7588 KB |
Output is correct |
| 82 |
Correct |
332 ms |
7600 KB |
Output is correct |
| 83 |
Correct |
359 ms |
7516 KB |
Output is correct |
| 84 |
Correct |
336 ms |
7556 KB |
Output is correct |
| 85 |
Correct |
417 ms |
7624 KB |
Output is correct |
| 86 |
Correct |
337 ms |
7480 KB |
Output is correct |
| 87 |
Correct |
338 ms |
7548 KB |
Output is correct |
| 88 |
Correct |
336 ms |
7500 KB |
Output is correct |
| 89 |
Correct |
335 ms |
7564 KB |
Output is correct |
| 90 |
Correct |
320 ms |
7500 KB |
Output is correct |
| 91 |
Correct |
307 ms |
7500 KB |
Output is correct |
| 92 |
Correct |
410 ms |
7580 KB |
Output is correct |
