#include <iostream>
#include <vector>
#include <queue>
#include <climits>
using std::cout;
using std::endl;
using std::vector;
using std::pair;
vector<pair<int, int>> neighbors(const pair<int, int>& at, int row_num, int col_num) {
vector<pair<int, int>> neighbors;
if (at.first > 0) {
neighbors.push_back({at.first - 1, at.second});
}
if (at.second > 0) {
neighbors.push_back({at.first, at.second - 1});
}
if (at.first < row_num - 1) {
neighbors.push_back({at.first + 1, at.second});
}
if (at.second < col_num - 1) {
neighbors.push_back({at.first, at.second + 1});
}
return neighbors;
}
class Field {
private:
const vector<vector<char>> field;
const int row_num;
const int col_num;
pair<int, int> start;
vector<vector<int>> bee_dists;
public:
Field(const vector<vector<char>>& field)
: field(field), row_num(field.size()), col_num(field[0].size()),
bee_dists(row_num, vector<int>(col_num, INT_MAX)) {
std::queue<pair<int, int>> frontier;
for (int r = 0; r < row_num; r++) {
for (int c = 0; c < col_num; c++) {
if (field[r][c] == 'H') {
frontier.push({r, c});
bee_dists[r][c] = 0;
} else if (field[r][c] == 'M') {
start = {r, c};
}
}
}
while (!frontier.empty()) {
pair<int, int> c = frontier.front(); // c for curr and to reduce my line length
frontier.pop();
int n_cost = bee_dists[c.first][c.second] + 1;
for (const pair<int, int>& n : neighbors(c, row_num, col_num)) {
if (n_cost < bee_dists[n.first][n.second]
&& field[n.first][n.second] != 'T'
&& field[n.first][n.second] != 'D') {
bee_dists[n.first][n.second] = n_cost;
frontier.push(n);
}
}
}
}
bool can_go_home(int honey_time, int speed) {
std::queue<pair<int, int>> frontier;
vector<vector<int>> min_moves(row_num, vector<int>(col_num, INT_MAX));
frontier.push(start);
min_moves[start.first][start.second] = honey_time * speed;
while (!frontier.empty()) {
pair<int, int> curr = frontier.front();
frontier.pop();
if (field[curr.first][curr.second] == 'D') {
return true;
}
int n_cost = min_moves[curr.first][curr.second] + 1;
for (const pair<int, int>& n : neighbors(curr, row_num, col_num)) {
if (field[n.first][n.second] != 'T'
&& (n_cost / speed) < bee_dists[n.first][n.second]
&& n_cost < min_moves[n.first][n.second]) {
min_moves[n.first][n.second] = n_cost;
frontier.push(n);
}
}
}
return false;
}
};
// https://oj.uz/problem/view/IOI09_mecho (sample input ommitted)
int main() {
int side_len;
int speed;
std::cin >> side_len >> speed;
vector<vector<char>> grid(side_len, vector<char>(side_len));
for (int r = 0; r < side_len; r++) {
for (int c = 0; c < side_len; c++) {
std::cin >> grid[r][c];
}
}
Field field(grid);
int lo = 0;
int hi = side_len * side_len;
int valid = -1;
while (lo <= hi) {
int mid = (lo + hi) / 2;
if (field.can_go_home(mid, speed)) {
valid = mid;
lo = mid + 1;
} else {
hi = mid - 1;
}
}
if (valid == -1) {
throw -1;
}
cout << valid << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
364 KB |
Output is correct |
2 |
Correct |
1 ms |
364 KB |
Output is correct |
3 |
Correct |
1 ms |
364 KB |
Output is correct |
4 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
364 KB |
Output is correct |
6 |
Correct |
1 ms |
364 KB |
Output is correct |
7 |
Correct |
427 ms |
6840 KB |
Output is correct |
8 |
Runtime error |
5 ms |
620 KB |
Execution killed with signal 6 |
9 |
Correct |
1 ms |
364 KB |
Output is correct |
10 |
Correct |
1 ms |
364 KB |
Output is correct |
11 |
Correct |
1 ms |
364 KB |
Output is correct |
12 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
13 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
14 |
Runtime error |
4 ms |
620 KB |
Execution killed with signal 6 |
15 |
Correct |
1 ms |
364 KB |
Output is correct |
16 |
Correct |
1 ms |
364 KB |
Output is correct |
17 |
Correct |
1 ms |
364 KB |
Output is correct |
18 |
Correct |
1 ms |
364 KB |
Output is correct |
19 |
Correct |
1 ms |
364 KB |
Output is correct |
20 |
Correct |
1 ms |
364 KB |
Output is correct |
21 |
Correct |
1 ms |
364 KB |
Output is correct |
22 |
Correct |
1 ms |
364 KB |
Output is correct |
23 |
Correct |
1 ms |
364 KB |
Output is correct |
24 |
Correct |
1 ms |
364 KB |
Output is correct |
25 |
Correct |
1 ms |
364 KB |
Output is correct |
26 |
Correct |
2 ms |
364 KB |
Output is correct |
27 |
Correct |
2 ms |
364 KB |
Output is correct |
28 |
Correct |
2 ms |
364 KB |
Output is correct |
29 |
Correct |
2 ms |
364 KB |
Output is correct |
30 |
Correct |
2 ms |
364 KB |
Output is correct |
31 |
Correct |
2 ms |
364 KB |
Output is correct |
32 |
Correct |
2 ms |
492 KB |
Output is correct |
33 |
Correct |
22 ms |
1612 KB |
Output is correct |
34 |
Correct |
20 ms |
1612 KB |
Output is correct |
35 |
Correct |
101 ms |
1616 KB |
Output is correct |
36 |
Correct |
24 ms |
1996 KB |
Output is correct |
37 |
Correct |
26 ms |
1996 KB |
Output is correct |
38 |
Correct |
129 ms |
2132 KB |
Output is correct |
39 |
Correct |
30 ms |
2412 KB |
Output is correct |
40 |
Correct |
33 ms |
2560 KB |
Output is correct |
41 |
Correct |
184 ms |
2412 KB |
Output is correct |
42 |
Correct |
47 ms |
2948 KB |
Output is correct |
43 |
Correct |
41 ms |
2956 KB |
Output is correct |
44 |
Correct |
216 ms |
2952 KB |
Output is correct |
45 |
Correct |
48 ms |
3468 KB |
Output is correct |
46 |
Correct |
49 ms |
3452 KB |
Output is correct |
47 |
Correct |
252 ms |
3500 KB |
Output is correct |
48 |
Correct |
54 ms |
3972 KB |
Output is correct |
49 |
Correct |
57 ms |
3972 KB |
Output is correct |
50 |
Correct |
303 ms |
4112 KB |
Output is correct |
51 |
Correct |
64 ms |
4664 KB |
Output is correct |
52 |
Correct |
70 ms |
4664 KB |
Output is correct |
53 |
Correct |
368 ms |
4644 KB |
Output is correct |
54 |
Correct |
76 ms |
5332 KB |
Output is correct |
55 |
Correct |
78 ms |
5392 KB |
Output is correct |
56 |
Correct |
450 ms |
5468 KB |
Output is correct |
57 |
Correct |
88 ms |
6092 KB |
Output is correct |
58 |
Correct |
92 ms |
6100 KB |
Output is correct |
59 |
Correct |
633 ms |
5992 KB |
Output is correct |
60 |
Correct |
99 ms |
6912 KB |
Output is correct |
61 |
Correct |
101 ms |
6884 KB |
Output is correct |
62 |
Correct |
591 ms |
6828 KB |
Output is correct |
63 |
Correct |
352 ms |
6828 KB |
Output is correct |
64 |
Correct |
637 ms |
6932 KB |
Output is correct |
65 |
Correct |
489 ms |
6828 KB |
Output is correct |
66 |
Correct |
412 ms |
6828 KB |
Output is correct |
67 |
Runtime error |
403 ms |
8916 KB |
Execution killed with signal 6 |
68 |
Correct |
181 ms |
6860 KB |
Output is correct |
69 |
Correct |
180 ms |
6940 KB |
Output is correct |
70 |
Correct |
156 ms |
6920 KB |
Output is correct |
71 |
Correct |
160 ms |
6892 KB |
Output is correct |
72 |
Incorrect |
123 ms |
6892 KB |
Output isn't correct |
73 |
Incorrect |
198 ms |
6828 KB |
Output isn't correct |
74 |
Correct |
283 ms |
6872 KB |
Output is correct |
75 |
Correct |
348 ms |
6852 KB |
Output is correct |
76 |
Correct |
302 ms |
6932 KB |
Output is correct |
77 |
Correct |
320 ms |
6960 KB |
Output is correct |
78 |
Runtime error |
370 ms |
9240 KB |
Execution killed with signal 6 |
79 |
Correct |
235 ms |
6948 KB |
Output is correct |
80 |
Correct |
295 ms |
7064 KB |
Output is correct |
81 |
Correct |
328 ms |
6840 KB |
Output is correct |
82 |
Correct |
291 ms |
6900 KB |
Output is correct |
83 |
Correct |
417 ms |
6848 KB |
Output is correct |
84 |
Correct |
356 ms |
6860 KB |
Output is correct |
85 |
Correct |
378 ms |
6924 KB |
Output is correct |
86 |
Correct |
408 ms |
6884 KB |
Output is correct |
87 |
Correct |
368 ms |
6936 KB |
Output is correct |
88 |
Correct |
402 ms |
6984 KB |
Output is correct |
89 |
Correct |
410 ms |
6824 KB |
Output is correct |
90 |
Correct |
415 ms |
6944 KB |
Output is correct |
91 |
Correct |
438 ms |
6952 KB |
Output is correct |
92 |
Correct |
438 ms |
6964 KB |
Output is correct |