Submission #815784

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815784	2023-08-08T23:14:37 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	89 / 100	156 ms	6548 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] && minBearDist[r][c] / S + wait < minHiveDist[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 = -1, 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

89.0 / 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	0 ms	340 KB	Output is correct
7	Correct	63 ms	5252 KB	Output is correct
8	Correct	0 ms	340 KB	Output is correct
9	Correct	0 ms	340 KB	Output is correct
10	Correct	0 ms	340 KB	Output is correct
11	Correct	0 ms	340 KB	Output is correct
12	Correct	1 ms	468 KB	Output is 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	1 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	1 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	2772 KB	Output is correct
36	Correct	5 ms	2168 KB	Output is correct
37	Correct	6 ms	2516 KB	Output is correct
38	Correct	22 ms	3200 KB	Output is correct
39	Correct	6 ms	2388 KB	Output is correct
40	Correct	8 ms	2788 KB	Output is correct
41	Correct	30 ms	3572 KB	Output is correct
42	Correct	8 ms	2644 KB	Output is correct
43	Correct	9 ms	3136 KB	Output is correct
44	Correct	37 ms	3908 KB	Output is correct
45	Correct	10 ms	2936 KB	Output is correct
46	Correct	14 ms	3412 KB	Output is correct
47	Correct	42 ms	4276 KB	Output is correct
48	Correct	11 ms	3248 KB	Output is correct
49	Correct	11 ms	3652 KB	Output is correct
50	Correct	54 ms	4564 KB	Output is correct
51	Correct	12 ms	3380 KB	Output is correct
52	Correct	14 ms	3884 KB	Output is correct
53	Correct	62 ms	5004 KB	Output is correct
54	Correct	15 ms	3672 KB	Output is correct
55	Correct	16 ms	4180 KB	Output is correct
56	Correct	83 ms	5368 KB	Output is correct
57	Correct	17 ms	3892 KB	Output is correct
58	Correct	18 ms	4468 KB	Output is correct
59	Correct	86 ms	5724 KB	Output is correct
60	Correct	18 ms	4096 KB	Output is correct
61	Correct	20 ms	4784 KB	Output is correct
62	Correct	96 ms	6080 KB	Output is correct
63	Correct	83 ms	6092 KB	Output is correct
64	Correct	156 ms	6088 KB	Output is correct
65	Correct	116 ms	6072 KB	Output is correct
66	Correct	98 ms	6084 KB	Output is correct
67	Correct	93 ms	6080 KB	Output is correct
68	Correct	41 ms	6220 KB	Output is correct
69	Correct	38 ms	6100 KB	Output is correct
70	Correct	29 ms	6076 KB	Output is correct
71	Correct	33 ms	6068 KB	Output is correct
72	Incorrect	26 ms	4144 KB	Output isn't correct
73	Incorrect	31 ms	6548 KB	Output isn't correct
74	Correct	44 ms	6532 KB	Output is correct
75	Correct	54 ms	6532 KB	Output is correct
76	Correct	50 ms	6528 KB	Output is correct
77	Correct	46 ms	6536 KB	Output is correct
78	Correct	65 ms	5208 KB	Output is correct
79	Correct	38 ms	4736 KB	Output is correct
80	Correct	46 ms	4928 KB	Output is correct
81	Correct	52 ms	5024 KB	Output is correct
82	Correct	47 ms	5028 KB	Output is correct
83	Correct	59 ms	5024 KB	Output is correct
84	Correct	52 ms	4936 KB	Output is correct
85	Correct	57 ms	5076 KB	Output is correct
86	Correct	62 ms	5120 KB	Output is correct
87	Correct	56 ms	4992 KB	Output is correct
88	Correct	60 ms	5128 KB	Output is correct
89	Correct	60 ms	5076 KB	Output is correct
90	Correct	63 ms	5104 KB	Output is correct
91	Correct	63 ms	5136 KB	Output is correct
92	Correct	66 ms	5132 KB	Output is correct