| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 492145 |
2021-12-05T16:10:17 Z |
nehasane |
Mecho (IOI09_mecho) |
C++14 |
|
562 ms |
7380 KB |
#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 800;
vector<string> field(MAX_N);
int n, s;
bool valid_sq(int x, int y) {
return x >= 0 && x < n && y >= 0 && y < n
&& (field[x][y] == 'G' || field[x][y] == 'M');
}
bool mecho_reached(int mecho_dis, int bees_dis){
return mecho_dis / s < bees_dis;
}
int main() {
cin >> n >> s;
for (int i = 0; i < n; i++){
cin >> field[i];
}
vector<pair<int, int>> hives;
int mechox, mechoy, home_x, home_y;
// find x and y coordinates for for Mecho, the bees and the cave
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (field[i][j] == 'M') {
mechox = i;
mechoy = 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 dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};
// binary search on waiting time
int l = 0;
int r = n * n;
while (l <= r) {
vector<vector<bool>> bees_visited(n, vector<bool>(n));
vector<vector<bool>> mecho_visited(n, vector<bool>(n));
vector<vector<int>> bees_time(n, vector<int>(n));
vector<vector<int>> mecho_time(n, vector<int>(n));
queue<pair<int, int>> q;
int eating_time = (l + r) / 2;
// move bees
for (auto i : hives) {
q.push({i.first, i.second});
bees_visited[i.first][i.second] = true;
}
while (!q.empty()) {
int x = q.front().first, y = q.front().second;
q.pop();
for (int i = 0; i < 4; i++) {
int nx = x + dx[i], ny = y + dy[i];
if (valid_sq(nx, ny) && !bees_visited[nx][ny]) {
bees_time[nx][ny] = bees_time[x][y] + 1;
q.push({nx, ny});
bees_visited[nx][ny] = true;
}
}
}
// move Mecho
q.push({mechox, mechoy});
mecho_visited[mechox][mechoy] = true;
if (bees_time[mechox][mechoy] <= eating_time) {
q.pop();
}
while (!q.empty()) {
int x = q.front().first, y = q.front().second;
q.pop();
for (int i = 0; i < 4; i++) {
int nx = x + dx[i], ny = y + dy[i];
/*
* check if mecho reaces node[x][y] before the bees
* divide the time mecho takes to reach a node by s, since
* mecho walks s steps at a time.
* substract the eating time from the time taken for the
* bees to reach the node, because that time was used by
* mecho for eating
*/
if (valid_sq(nx, ny) && !mecho_visited[nx][ny] &&
mecho_reached(mecho_time[x][y] + 1, bees_time[nx][ny]
- eating_time)) {
mecho_visited[nx][ny] = true;
q.push({nx, ny});
mecho_time[nx][ny] = mecho_time[x][y] + 1;
}
}
}
// check if mecho reached a node surrounding his cave before the bees
bool reached = false;
for (int i = 0; i < 4; i++) {
int nx = home_x + dx[i], ny = home_y + dy[i];
if (valid_sq(nx, ny) && mecho_reached(mecho_time[nx][ny],
bees_time[nx][ny] - eating_time)) {
reached = true;
}
}
if (reached) {
l = eating_time + 1;
} else {
r = eating_time - 1;
}
}
cout << l - 1 << '\n';
}
Compilation message
mecho.cpp: In function 'int main()':
mecho.cpp:77:31: warning: 'mechoy' may be used uninitialized in this function [-Wmaybe-uninitialized]
77 | mecho_visited[mechox][mechoy] = true;
| ^
mecho.cpp:77:23: warning: 'mechox' may be used uninitialized in this function [-Wmaybe-uninitialized]
77 | mecho_visited[mechox][mechoy] = true;
| ^
mecho.cpp:109:29: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
109 | int nx = home_x + dx[i], ny = home_y + dy[i];
| ^~
mecho.cpp:109:8: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
109 | int nx = home_x + dx[i], ny = home_y + dy[i];
| ^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 2 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 3 |
Incorrect |
0 ms |
332 KB |
Output isn't correct |
| 4 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 5 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 6 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
| 7 |
Incorrect |
520 ms |
7116 KB |
Output isn't correct |
| 8 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 9 |
Incorrect |
1 ms |
316 KB |
Output isn't correct |
| 10 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 11 |
Incorrect |
1 ms |
312 KB |
Output isn't correct |
| 12 |
Correct |
2 ms |
332 KB |
Output is correct |
| 13 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 14 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 15 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 16 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 17 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 18 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 19 |
Incorrect |
1 ms |
236 KB |
Output isn't correct |
| 20 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 21 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 22 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 23 |
Incorrect |
1 ms |
320 KB |
Output isn't correct |
| 24 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 25 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 26 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 27 |
Incorrect |
3 ms |
332 KB |
Output isn't correct |
| 28 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 29 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 30 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 31 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 32 |
Incorrect |
2 ms |
332 KB |
Output isn't correct |
| 33 |
Incorrect |
41 ms |
1660 KB |
Output isn't correct |
| 34 |
Incorrect |
43 ms |
1664 KB |
Output isn't correct |
| 35 |
Incorrect |
72 ms |
1656 KB |
Output isn't correct |
| 36 |
Incorrect |
55 ms |
2032 KB |
Output isn't correct |
| 37 |
Incorrect |
53 ms |
1996 KB |
Output isn't correct |
| 38 |
Incorrect |
106 ms |
2116 KB |
Output isn't correct |
| 39 |
Incorrect |
67 ms |
2464 KB |
Output isn't correct |
| 40 |
Incorrect |
64 ms |
2472 KB |
Output isn't correct |
| 41 |
Incorrect |
132 ms |
2436 KB |
Output isn't correct |
| 42 |
Incorrect |
90 ms |
3156 KB |
Output isn't correct |
| 43 |
Incorrect |
103 ms |
3152 KB |
Output isn't correct |
| 44 |
Incorrect |
169 ms |
3148 KB |
Output isn't correct |
| 45 |
Incorrect |
110 ms |
3664 KB |
Output isn't correct |
| 46 |
Incorrect |
102 ms |
3660 KB |
Output isn't correct |
| 47 |
Incorrect |
223 ms |
3660 KB |
Output isn't correct |
| 48 |
Incorrect |
130 ms |
4420 KB |
Output isn't correct |
| 49 |
Incorrect |
134 ms |
4260 KB |
Output isn't correct |
| 50 |
Incorrect |
245 ms |
4264 KB |
Output isn't correct |
| 51 |
Incorrect |
195 ms |
4916 KB |
Output isn't correct |
| 52 |
Incorrect |
153 ms |
4936 KB |
Output isn't correct |
| 53 |
Incorrect |
288 ms |
4812 KB |
Output isn't correct |
| 54 |
Incorrect |
192 ms |
5604 KB |
Output isn't correct |
| 55 |
Incorrect |
175 ms |
5560 KB |
Output isn't correct |
| 56 |
Incorrect |
330 ms |
5528 KB |
Output isn't correct |
| 57 |
Incorrect |
203 ms |
6260 KB |
Output isn't correct |
| 58 |
Incorrect |
197 ms |
6260 KB |
Output isn't correct |
| 59 |
Incorrect |
405 ms |
6340 KB |
Output isn't correct |
| 60 |
Incorrect |
239 ms |
7012 KB |
Output isn't correct |
| 61 |
Incorrect |
225 ms |
7012 KB |
Output isn't correct |
| 62 |
Incorrect |
485 ms |
7008 KB |
Output isn't correct |
| 63 |
Incorrect |
435 ms |
7016 KB |
Output isn't correct |
| 64 |
Incorrect |
455 ms |
7072 KB |
Output isn't correct |
| 65 |
Incorrect |
477 ms |
7212 KB |
Output isn't correct |
| 66 |
Incorrect |
462 ms |
7020 KB |
Output isn't correct |
| 67 |
Incorrect |
417 ms |
7136 KB |
Output isn't correct |
| 68 |
Incorrect |
452 ms |
7032 KB |
Output isn't correct |
| 69 |
Incorrect |
481 ms |
7040 KB |
Output isn't correct |
| 70 |
Incorrect |
456 ms |
7036 KB |
Output isn't correct |
| 71 |
Incorrect |
460 ms |
7052 KB |
Output isn't correct |
| 72 |
Incorrect |
464 ms |
7036 KB |
Output isn't correct |
| 73 |
Incorrect |
492 ms |
7316 KB |
Output isn't correct |
| 74 |
Incorrect |
515 ms |
7364 KB |
Output isn't correct |
| 75 |
Incorrect |
498 ms |
7360 KB |
Output isn't correct |
| 76 |
Incorrect |
489 ms |
7320 KB |
Output isn't correct |
| 77 |
Incorrect |
538 ms |
7380 KB |
Output isn't correct |
| 78 |
Incorrect |
495 ms |
7276 KB |
Output isn't correct |
| 79 |
Incorrect |
476 ms |
7276 KB |
Output isn't correct |
| 80 |
Incorrect |
448 ms |
7276 KB |
Output isn't correct |
| 81 |
Incorrect |
478 ms |
7364 KB |
Output isn't correct |
| 82 |
Incorrect |
464 ms |
7188 KB |
Output isn't correct |
| 83 |
Incorrect |
507 ms |
7244 KB |
Output isn't correct |
| 84 |
Incorrect |
524 ms |
7288 KB |
Output isn't correct |
| 85 |
Incorrect |
505 ms |
7232 KB |
Output isn't correct |
| 86 |
Incorrect |
532 ms |
7236 KB |
Output isn't correct |
| 87 |
Incorrect |
526 ms |
7244 KB |
Output isn't correct |
| 88 |
Incorrect |
526 ms |
7184 KB |
Output isn't correct |
| 89 |
Incorrect |
558 ms |
7296 KB |
Output isn't correct |
| 90 |
Incorrect |
512 ms |
7176 KB |
Output isn't correct |
| 91 |
Incorrect |
531 ms |
7304 KB |
Output isn't correct |
| 92 |
Incorrect |
562 ms |
7192 KB |
Output isn't correct |
