Submission #815781

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815781	2023-08-08T23:08:05 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	68 / 100	156 ms	6524 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, int minDist[801][801]) {
	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();
		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] == 'G' || grid[r][c] == 'M')) {
				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] == 'G' || grid[r][c] == 'M')) {
				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);
	for (int i = 0; i < 4; i++) {
		int r = dR + dx[i], c = dC + dy[i];
		if (isValid(r, c) && visited[r][c]) return true;
	} return false;
}

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	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	0 ms	340 KB	Output is correct
7	Correct	63 ms	5068 KB	Output is correct
8	Incorrect	0 ms	340 KB	Output isn't correct
9	Correct	0 ms	340 KB	Output is correct
10	Correct	0 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	Incorrect	1 ms	596 KB	Output isn't correct
15	Correct	0 ms	340 KB	Output is correct
16	Correct	0 ms	340 KB	Output is correct
17	Correct	1 ms	340 KB	Output is correct
18	Correct	0 ms	468 KB	Output is correct
19	Correct	0 ms	468 KB	Output is correct
20	Correct	0 ms	468 KB	Output is correct
21	Correct	0 ms	468 KB	Output is correct
22	Correct	0 ms	468 KB	Output is correct
23	Correct	1 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	2844 KB	Output is correct
36	Correct	6 ms	2260 KB	Output is correct
37	Correct	8 ms	2516 KB	Output is correct
38	Correct	26 ms	3196 KB	Output is correct
39	Correct	7 ms	2388 KB	Output is correct
40	Correct	8 ms	2860 KB	Output is correct
41	Correct	31 ms	3512 KB	Output is correct
42	Correct	8 ms	2740 KB	Output is correct
43	Correct	9 ms	3132 KB	Output is correct
44	Correct	37 ms	3924 KB	Output is correct
45	Correct	10 ms	2984 KB	Output is correct
46	Correct	11 ms	3412 KB	Output is correct
47	Correct	46 ms	4264 KB	Output is correct
48	Correct	11 ms	3132 KB	Output is correct
49	Correct	11 ms	3668 KB	Output is correct
50	Correct	54 ms	4564 KB	Output is correct
51	Correct	13 ms	3412 KB	Output is correct
52	Correct	14 ms	3984 KB	Output is correct
53	Correct	70 ms	5004 KB	Output is correct
54	Correct	15 ms	3736 KB	Output is correct
55	Correct	18 ms	4276 KB	Output is correct
56	Correct	76 ms	5356 KB	Output is correct
57	Correct	17 ms	3924 KB	Output is correct
58	Correct	18 ms	4564 KB	Output is correct
59	Correct	85 ms	5724 KB	Output is correct
60	Correct	18 ms	4180 KB	Output is correct
61	Correct	21 ms	4784 KB	Output is correct
62	Correct	94 ms	6000 KB	Output is correct
63	Correct	77 ms	6088 KB	Output is correct
64	Correct	156 ms	6088 KB	Output is correct
65	Correct	114 ms	6084 KB	Output is correct
66	Correct	101 ms	6100 KB	Output is correct
67	Incorrect	93 ms	6084 KB	Output isn't correct
68	Correct	40 ms	5868 KB	Output is correct
69	Correct	36 ms	6056 KB	Output is correct
70	Correct	39 ms	6048 KB	Output is correct
71	Correct	31 ms	6256 KB	Output is correct
72	Incorrect	26 ms	4148 KB	Output isn't correct
73	Incorrect	26 ms	6516 KB	Output isn't correct
74	Correct	46 ms	6524 KB	Output is correct
75	Correct	53 ms	6476 KB	Output is correct
76	Correct	50 ms	6476 KB	Output is correct
77	Correct	60 ms	6456 KB	Output is correct
78	Incorrect	63 ms	5144 KB	Output isn't correct
79	Correct	39 ms	4756 KB	Output is correct
80	Correct	45 ms	4924 KB	Output is correct
81	Correct	51 ms	4940 KB	Output is correct
82	Correct	47 ms	4916 KB	Output is correct
83	Correct	58 ms	4948 KB	Output is correct
84	Correct	63 ms	5112 KB	Output is correct
85	Correct	59 ms	5076 KB	Output is correct
86	Correct	63 ms	5076 KB	Output is correct
87	Correct	58 ms	5068 KB	Output is correct
88	Correct	59 ms	5080 KB	Output is correct
89	Correct	65 ms	5008 KB	Output is correct
90	Correct	68 ms	5088 KB	Output is correct
91	Correct	66 ms	5304 KB	Output is correct
92	Correct	60 ms	5092 KB	Output is correct