Submission #815672

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815672	2023-08-08T18:08:18 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	68 / 100	154 ms	6536 KB

mecho

#include <iostream>
#include <vector>
#include <queue>
#define pii pair<int, int>

using namespace std;

int N, S;
int mR, mC, dR, dC;
char grid[801][801];
int minHiveDist[801][801], minBearDist[801][801];

const int dx[4] = { -1, 1, 0, 0 };
const int dy[4] = { 0, 0, -1, 1 };
bool isValid(int r, int c) { return 0 <= r && r < N && 0 <= c && c < N; }

void bfs(vector<pii> initialCoords, int minDist[801][801]) {
	queue<pair<pii, int>> q; 
	vector<vector<bool>> visited(801, vector<bool>(801));
	for (pii p : initialCoords) {
		q.push({ p, 0 }); visited[p.first][p.second] = true;
	}
	while (!q.empty()) {
		pii loc = q.front().first; int dist = q.front().second; q.pop();
		minDist[loc.first][loc.second] = dist;
		for (int i = 0; i < 4; i++) {
			int r = loc.first + dx[i], c = loc.second + dy[i];
			if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T') {
				visited[r][c] = true;
				q.push({ {r, c}, dist + 1 });
			}
		}
	}
}

vector<vector<bool>> visited;
void bfs2(int startR, int startC, int wait) {
	visited.clear(); visited.resize(N, vector<bool>(N));
	queue<pair<pii, int>> q; q.push({ {startR, startC}, 0 });
	visited[startR][startC] = true;
	while (!q.empty()) {
		pii loc = q.front().first; int dist = q.front().second; q.pop();
		minBearDist[loc.first][loc.second] = dist;
		for (int i = 0; i < 4; i++) {
			int r = loc.first + dx[i], c = loc.second + dy[i];
			if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T') {
				if ((dist + 1) / S + wait < minHiveDist[r][c]) {
					visited[r][c] = true;
					q.push({ {r, c}, dist + 1 });
				}
			}
		}
	}
}
bool works(int wait) {
	bfs2(mR, mC, wait);
	return visited[dR][dC];
}

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);

	cin >> N >> S;
	for (int i = 0; i < N; i++)
		for (int j = 0; j < N; j++)
			cin >> grid[i][j];
	
	vector<pii> hives;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			if (grid[i][j] == 'H') hives.push_back({ i, j });
			if (grid[i][j] == 'M') { mR = i; mC = j; }
			if (grid[i][j] == 'D') { dR = i; dC = j; }
		}
	}

	bfs(hives, minHiveDist); minHiveDist[dR][dC] = (int)1e9;

	int low = 0, high = N * N;
	while (low < high) {
		int mid = (low + high + 1) / 2;
		if (works(mid)) low = mid;
		else high = mid - 1;
	} cout << low << endl;
}

Subtask #1

68.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	468 KB	Output is correct
2	Correct	0 ms	468 KB	Output is correct
3	Correct	0 ms	468 KB	Output is correct
4	Correct	0 ms	468 KB	Output is correct
5	Correct	0 ms	468 KB	Output is correct
6	Correct	1 ms	468 KB	Output is correct
7	Correct	62 ms	5124 KB	Output is correct
8	Incorrect	0 ms	468 KB	Output isn't correct
9	Correct	0 ms	468 KB	Output is correct
10	Correct	0 ms	468 KB	Output is correct
11	Correct	0 ms	468 KB	Output is correct
12	Incorrect	1 ms	596 KB	Output isn't correct
13	Incorrect	1 ms	724 KB	Output isn't correct
14	Incorrect	1 ms	724 KB	Output isn't correct
15	Correct	0 ms	468 KB	Output is correct
16	Correct	1 ms	468 KB	Output is correct
17	Correct	1 ms	468 KB	Output is correct
18	Correct	0 ms	468 KB	Output is correct
19	Correct	1 ms	596 KB	Output is correct
20	Correct	1 ms	596 KB	Output is correct
21	Correct	1 ms	596 KB	Output is correct
22	Correct	1 ms	596 KB	Output is correct
23	Correct	1 ms	596 KB	Output is correct
24	Correct	1 ms	724 KB	Output is correct
25	Correct	1 ms	724 KB	Output is correct
26	Correct	1 ms	724 KB	Output is correct
27	Correct	1 ms	724 KB	Output is correct
28	Correct	1 ms	724 KB	Output is correct
29	Correct	1 ms	724 KB	Output is correct
30	Correct	1 ms	852 KB	Output is correct
31	Correct	1 ms	724 KB	Output is correct
32	Correct	1 ms	852 KB	Output is correct
33	Correct	4 ms	2004 KB	Output is correct
34	Correct	5 ms	2260 KB	Output is correct
35	Correct	18 ms	2900 KB	Output is correct
36	Correct	5 ms	2260 KB	Output is correct
37	Correct	6 ms	2644 KB	Output is correct
38	Correct	23 ms	3280 KB	Output is correct
39	Correct	6 ms	2516 KB	Output is correct
40	Correct	11 ms	2900 KB	Output is correct
41	Correct	30 ms	3612 KB	Output is correct
42	Correct	10 ms	2772 KB	Output is correct
43	Correct	9 ms	3128 KB	Output is correct
44	Correct	39 ms	3968 KB	Output is correct
45	Correct	9 ms	2936 KB	Output is correct
46	Correct	10 ms	3392 KB	Output is correct
47	Correct	41 ms	4316 KB	Output is correct
48	Correct	11 ms	3204 KB	Output is correct
49	Correct	12 ms	3668 KB	Output is correct
50	Correct	53 ms	4692 KB	Output is correct
51	Correct	12 ms	3412 KB	Output is correct
52	Correct	13 ms	3924 KB	Output is correct
53	Correct	70 ms	4932 KB	Output is correct
54	Correct	15 ms	3668 KB	Output is correct
55	Correct	17 ms	4280 KB	Output is correct
56	Correct	87 ms	5384 KB	Output is correct
57	Correct	16 ms	3924 KB	Output is correct
58	Correct	18 ms	4472 KB	Output is correct
59	Correct	86 ms	5736 KB	Output is correct
60	Correct	18 ms	4180 KB	Output is correct
61	Correct	23 ms	4748 KB	Output is correct
62	Correct	102 ms	6032 KB	Output is correct
63	Correct	79 ms	5964 KB	Output is correct
64	Correct	154 ms	6100 KB	Output is correct
65	Correct	115 ms	6056 KB	Output is correct
66	Correct	96 ms	6084 KB	Output is correct
67	Incorrect	97 ms	6036 KB	Output isn't correct
68	Correct	44 ms	5836 KB	Output is correct
69	Correct	36 ms	6080 KB	Output is correct
70	Correct	34 ms	6072 KB	Output is correct
71	Correct	31 ms	6128 KB	Output is correct
72	Incorrect	25 ms	4180 KB	Output isn't correct
73	Incorrect	26 ms	6472 KB	Output isn't correct
74	Correct	44 ms	6536 KB	Output is correct
75	Correct	55 ms	6476 KB	Output is correct
76	Correct	51 ms	6484 KB	Output is correct
77	Correct	61 ms	6528 KB	Output is correct
78	Incorrect	65 ms	5144 KB	Output isn't correct
79	Correct	38 ms	4752 KB	Output is correct
80	Correct	46 ms	4828 KB	Output is correct
81	Correct	64 ms	5016 KB	Output is correct
82	Correct	46 ms	4948 KB	Output is correct
83	Correct	58 ms	5136 KB	Output is correct
84	Correct	56 ms	5016 KB	Output is correct
85	Correct	57 ms	5000 KB	Output is correct
86	Correct	85 ms	5068 KB	Output is correct
87	Correct	72 ms	5064 KB	Output is correct
88	Correct	59 ms	5188 KB	Output is correct
89	Correct	66 ms	5000 KB	Output is correct
90	Correct	71 ms	5048 KB	Output is correct
91	Correct	64 ms	5168 KB	Output is correct
92	Correct	67 ms	5228 KB	Output is correct