Submission #815787

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815787	2023-08-08T23:17:28 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	84 / 100	169 ms	6540 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] != '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); 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	0 ms	340 KB	Output is correct
7	Correct	70 ms	5140 KB	Output is correct
8	Correct	0 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	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	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	19 ms	2772 KB	Output is correct
36	Correct	5 ms	2260 KB	Output is correct
37	Correct	6 ms	2572 KB	Output is correct
38	Correct	24 ms	3156 KB	Output is correct
39	Correct	6 ms	2388 KB	Output is correct
40	Correct	8 ms	2800 KB	Output is correct
41	Correct	41 ms	3548 KB	Output is correct
42	Correct	8 ms	2644 KB	Output is correct
43	Correct	9 ms	3028 KB	Output is correct
44	Correct	43 ms	3924 KB	Output is correct
45	Correct	9 ms	2940 KB	Output is correct
46	Correct	11 ms	3348 KB	Output is correct
47	Correct	46 ms	4284 KB	Output is correct
48	Correct	11 ms	3156 KB	Output is correct
49	Correct	12 ms	3640 KB	Output is correct
50	Correct	57 ms	4636 KB	Output is correct
51	Correct	12 ms	3412 KB	Output is correct
52	Correct	13 ms	3924 KB	Output is correct
53	Correct	67 ms	5000 KB	Output is correct
54	Correct	15 ms	3712 KB	Output is correct
55	Correct	16 ms	4208 KB	Output is correct
56	Correct	85 ms	5360 KB	Output is correct
57	Correct	17 ms	3924 KB	Output is correct
58	Correct	18 ms	4464 KB	Output is correct
59	Correct	90 ms	5684 KB	Output is correct
60	Correct	18 ms	4180 KB	Output is correct
61	Correct	21 ms	4824 KB	Output is correct
62	Correct	104 ms	6084 KB	Output is correct
63	Correct	87 ms	6032 KB	Output is correct
64	Correct	169 ms	6100 KB	Output is correct
65	Correct	126 ms	6088 KB	Output is correct
66	Correct	107 ms	5972 KB	Output is correct
67	Correct	98 ms	6012 KB	Output is correct
68	Correct	41 ms	6092 KB	Output is correct
69	Correct	42 ms	6228 KB	Output is correct
70	Correct	36 ms	6072 KB	Output is correct
71	Correct	35 ms	6188 KB	Output is correct
72	Incorrect	26 ms	4156 KB	Output isn't correct
73	Incorrect	31 ms	6476 KB	Output isn't correct
74	Correct	47 ms	6484 KB	Output is correct
75	Correct	56 ms	6484 KB	Output is correct
76	Correct	53 ms	6532 KB	Output is correct
77	Correct	57 ms	6540 KB	Output is correct
78	Correct	62 ms	5204 KB	Output is correct
79	Correct	40 ms	4816 KB	Output is correct
80	Correct	52 ms	4884 KB	Output is correct
81	Correct	56 ms	4960 KB	Output is correct
82	Correct	50 ms	5000 KB	Output is correct
83	Correct	64 ms	5080 KB	Output is correct
84	Correct	64 ms	4940 KB	Output is correct
85	Correct	65 ms	4972 KB	Output is correct
86	Correct	65 ms	5064 KB	Output is correct
87	Correct	65 ms	5080 KB	Output is correct
88	Correct	65 ms	5188 KB	Output is correct
89	Correct	72 ms	5076 KB	Output is correct
90	Correct	72 ms	5068 KB	Output is correct
91	Correct	65 ms	5108 KB	Output is correct
92	Correct	71 ms	5088 KB	Output is correct