Submission #815785

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
815785	2023-08-08T23:15:50 Z	Mustela_Erminea	Mecho (IOI09_mecho)	C++14	89 / 100	161 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, 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 = 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

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	280 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	5144 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	1 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	1 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	19 ms	2852 KB	Output is correct
36	Correct	5 ms	2260 KB	Output is correct
37	Correct	6 ms	2516 KB	Output is correct
38	Correct	26 ms	3192 KB	Output is correct
39	Correct	6 ms	2388 KB	Output is correct
40	Correct	8 ms	2772 KB	Output is correct
41	Correct	33 ms	3572 KB	Output is correct
42	Correct	8 ms	2644 KB	Output is correct
43	Correct	9 ms	3148 KB	Output is correct
44	Correct	46 ms	3928 KB	Output is correct
45	Correct	10 ms	2900 KB	Output is correct
46	Correct	10 ms	3432 KB	Output is correct
47	Correct	45 ms	4288 KB	Output is correct
48	Correct	11 ms	3156 KB	Output is correct
49	Correct	12 ms	3668 KB	Output is correct
50	Correct	58 ms	4572 KB	Output is correct
51	Correct	16 ms	3412 KB	Output is correct
52	Correct	16 ms	3980 KB	Output is correct
53	Correct	72 ms	4904 KB	Output is correct
54	Correct	15 ms	3668 KB	Output is correct
55	Correct	16 ms	4180 KB	Output is correct
56	Correct	80 ms	5356 KB	Output is correct
57	Correct	16 ms	3924 KB	Output is correct
58	Correct	18 ms	4572 KB	Output is correct
59	Correct	114 ms	5716 KB	Output is correct
60	Correct	18 ms	4092 KB	Output is correct
61	Correct	27 ms	4912 KB	Output is correct
62	Correct	102 ms	5972 KB	Output is correct
63	Correct	105 ms	6076 KB	Output is correct
64	Correct	161 ms	6084 KB	Output is correct
65	Correct	122 ms	6044 KB	Output is correct
66	Correct	108 ms	6100 KB	Output is correct
67	Correct	97 ms	6084 KB	Output is correct
68	Correct	41 ms	6092 KB	Output is correct
69	Correct	38 ms	6068 KB	Output is correct
70	Correct	38 ms	6132 KB	Output is correct
71	Correct	33 ms	6128 KB	Output is correct
72	Incorrect	25 ms	4152 KB	Output isn't correct
73	Incorrect	31 ms	6428 KB	Output isn't correct
74	Correct	46 ms	6472 KB	Output is correct
75	Correct	59 ms	6476 KB	Output is correct
76	Correct	53 ms	6532 KB	Output is correct
77	Correct	57 ms	6536 KB	Output is correct
78	Correct	62 ms	5104 KB	Output is correct
79	Correct	41 ms	4780 KB	Output is correct
80	Correct	53 ms	4896 KB	Output is correct
81	Correct	57 ms	5072 KB	Output is correct
82	Correct	49 ms	4944 KB	Output is correct
83	Correct	63 ms	4936 KB	Output is correct
84	Correct	63 ms	4956 KB	Output is correct
85	Correct	63 ms	4956 KB	Output is correct
86	Correct	67 ms	5068 KB	Output is correct
87	Correct	61 ms	5068 KB	Output is correct
88	Correct	75 ms	5092 KB	Output is correct
89	Correct	71 ms	5012 KB	Output is correct
90	Correct	72 ms	5068 KB	Output is correct
91	Correct	66 ms	5172 KB	Output is correct
92	Correct	65 ms	5100 KB	Output is correct