Submission #815805

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815805	2023-08-08T23:48:56 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	84 / 100	159 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; }

vector<vector<bool>> visited;
void bfs(vector<pii> initialCoords) {
	queue<pair<pii, int>> q; 
	visited.clear(); visited.resize(N, vector<bool>(N));
	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();
		minHiveDist[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 });
			}
		}
	}
}

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[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 << (works(low) ? low : low - 1) << endl;
}

Subtask #1

84.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	0 ms	340 KB	Output is correct
3	Correct	0 ms	340 KB	Output is correct
4	Correct	0 ms	340 KB	Output is correct
5	Correct	0 ms	340 KB	Output is correct
6	Correct	1 ms	340 KB	Output is correct
7	Correct	104 ms	5144 KB	Output is correct
8	Correct	1 ms	340 KB	Output is correct
9	Correct	0 ms	340 KB	Output is correct
10	Correct	1 ms	340 KB	Output is correct
11	Correct	1 ms	340 KB	Output is correct
12	Incorrect	1 ms	468 KB	Output isn't correct
13	Incorrect	1 ms	596 KB	Output isn't correct
14	Correct	1 ms	596 KB	Output is correct
15	Correct	0 ms	340 KB	Output is correct
16	Correct	0 ms	340 KB	Output is correct
17	Correct	0 ms	340 KB	Output is correct
18	Correct	0 ms	468 KB	Output is correct
19	Correct	1 ms	468 KB	Output is correct
20	Correct	0 ms	468 KB	Output is correct
21	Correct	1 ms	468 KB	Output is correct
22	Correct	0 ms	468 KB	Output is correct
23	Correct	0 ms	468 KB	Output is correct
24	Correct	1 ms	596 KB	Output is correct
25	Correct	1 ms	596 KB	Output is correct
26	Correct	1 ms	596 KB	Output is correct
27	Correct	1 ms	596 KB	Output is correct
28	Correct	1 ms	596 KB	Output is correct
29	Correct	1 ms	596 KB	Output is correct
30	Correct	1 ms	724 KB	Output is correct
31	Correct	1 ms	596 KB	Output is correct
32	Correct	1 ms	724 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	2772 KB	Output is correct
36	Correct	5 ms	2264 KB	Output is correct
37	Correct	6 ms	2516 KB	Output is correct
38	Correct	25 ms	3204 KB	Output is correct
39	Correct	6 ms	2388 KB	Output is correct
40	Correct	9 ms	2880 KB	Output is correct
41	Correct	32 ms	3564 KB	Output is correct
42	Correct	8 ms	2660 KB	Output is correct
43	Correct	9 ms	3036 KB	Output is correct
44	Correct	40 ms	3924 KB	Output is correct
45	Correct	9 ms	2944 KB	Output is correct
46	Correct	10 ms	3424 KB	Output is correct
47	Correct	45 ms	4288 KB	Output is correct
48	Correct	11 ms	3220 KB	Output is correct
49	Correct	12 ms	3612 KB	Output is correct
50	Correct	58 ms	4576 KB	Output is correct
51	Correct	12 ms	3396 KB	Output is correct
52	Correct	13 ms	3864 KB	Output is correct
53	Correct	69 ms	5000 KB	Output is correct
54	Correct	15 ms	3648 KB	Output is correct
55	Correct	19 ms	4228 KB	Output is correct
56	Correct	78 ms	5332 KB	Output is correct
57	Correct	20 ms	3976 KB	Output is correct
58	Correct	18 ms	4572 KB	Output is correct
59	Correct	90 ms	5716 KB	Output is correct
60	Correct	20 ms	4168 KB	Output is correct
61	Correct	20 ms	4756 KB	Output is correct
62	Correct	107 ms	6080 KB	Output is correct
63	Correct	91 ms	6080 KB	Output is correct
64	Correct	159 ms	6092 KB	Output is correct
65	Correct	124 ms	6100 KB	Output is correct
66	Correct	104 ms	6088 KB	Output is correct
67	Correct	103 ms	6092 KB	Output is correct
68	Correct	41 ms	6092 KB	Output is correct
69	Correct	38 ms	6124 KB	Output is correct
70	Correct	38 ms	6076 KB	Output is correct
71	Correct	33 ms	6072 KB	Output is correct
72	Incorrect	24 ms	4276 KB	Output isn't correct
73	Incorrect	31 ms	6444 KB	Output isn't correct
74	Correct	46 ms	6472 KB	Output is correct
75	Correct	64 ms	6476 KB	Output is correct
76	Correct	53 ms	6536 KB	Output is correct
77	Correct	60 ms	6516 KB	Output is correct
78	Correct	62 ms	5084 KB	Output is correct
79	Correct	47 ms	4824 KB	Output is correct
80	Correct	74 ms	4892 KB	Output is correct
81	Correct	55 ms	5036 KB	Output is correct
82	Correct	53 ms	5020 KB	Output is correct
83	Correct	65 ms	5040 KB	Output is correct
84	Correct	62 ms	4948 KB	Output is correct
85	Correct	62 ms	5076 KB	Output is correct
86	Correct	66 ms	5200 KB	Output is correct
87	Correct	62 ms	5052 KB	Output is correct
88	Correct	70 ms	5124 KB	Output is correct
89	Correct	73 ms	5064 KB	Output is correct
90	Correct	78 ms	5248 KB	Output is correct
91	Correct	66 ms	5168 KB	Output is correct
92	Correct	82 ms	5068 KB	Output is correct