Submission #876683

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
876683	2023-11-22T08:21:07 Z	MisterReaper	Mecho (IOI09_mecho)	C++17	100 / 100	140 ms	7000 KB

mecho

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

const int MAXN = 800 + 5;

char matrix[MAXN][MAXN];
int distBee[MAXN][MAXN];
int distBear[MAXN][MAXN];

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

#define ONLINE_JUDGE
void solve() {
	memset(distBee, -1, sizeof(distBee));

	int n, s;
	cin >> n >> s;

	pair <int, int> initial;
	pair <int, int> home;

	queue <array <int, 3>> q;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= n; j++) {
			cin >> matrix[i][j];
			if(matrix[i][j] == 'H') {
				q.push({0, i, j});
			} else if(matrix[i][j] == 'M') {
				initial = {i, j};
			} else if(matrix[i][j] == 'D') {
				home = {i, j};
			}
		}
	}

	auto in = [&](int x, int y) -> bool {
		return 1 <= min(x, y) && max(x, y) <= n;
	};

	while(!q.empty()) {
		auto [d, x, y] = q.front();
		q.pop();
		if(distBee[x][y] != -1) {
			continue;
		}

		distBee[x][y] = d;
		for(int dir = 0; dir < 4; dir++) {
			int _x = x + dx[dir], _y = y + dy[dir];
			if(in(_x, _y) && (matrix[_x][_y] != 'T' && matrix[_x][_y] != 'D') && distBee[_x][_y] == -1) {
				q.push({d +1, _x, _y});
			}
		}
	}

	auto check = [&](int k) -> bool {
		memset(distBear, -1, sizeof(distBear));

		q.push({s * k, initial.first, initial.second});
		while(!q.empty()) {
			auto [d, x, y] = q.front();
			q.pop();
			if(distBear[x][y] != -1 || (distBee[x][y] != -1 && d >= distBee[x][y] * s)) {
				continue;
			}

			//cerr << d << " :: " << x << " " << y << " | " << distBee[x][y] << "\n";
			distBear[x][y] = d;
			for(int dir = 0; dir < 4; dir++) {
				int _x = x + dx[dir], _y = y + dy[dir];
				if(in(_x, _y) && (matrix[_x][_y] != 'T') && distBear[_x][_y] == -1) {
					q.push({d +1, _x, _y});
				}
			}
		}

		//cerr << "\n";

		if(distBear[home.first][home.second] == -1) {
			return false;
		}

		return true;
	};
	
	int l = 0, r = n * n + 2, ans = -1;
	while(l <= r) {
		int mid = (l + r) / 2;
		if(check(mid)) {
			ans = mid;
			l = mid +1;
		} else {
			r = mid -1;
		}
	}

	cout << ans;

	return;
}

signed main() {
	#ifndef ONLINE_JUDGE
		freopen(".in", "r", stdin);
		freopen(".out", "w", stdout);
	#endif

	ios_base::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);

	int t = 1; //cin >> t;
	for(int i = 1; i <= t; i++) {
		solve();
	}

	return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	5468 KB	Output is correct
2	Correct	1 ms	5468 KB	Output is correct
3	Correct	1 ms	5468 KB	Output is correct
4	Correct	1 ms	5720 KB	Output is correct
5	Correct	1 ms	5468 KB	Output is correct
6	Correct	1 ms	5468 KB	Output is correct
7	Correct	82 ms	6464 KB	Output is correct
8	Correct	1 ms	5468 KB	Output is correct
9	Correct	1 ms	5468 KB	Output is correct
10	Correct	1 ms	5468 KB	Output is correct
11	Correct	1 ms	5468 KB	Output is correct
12	Correct	2 ms	5468 KB	Output is correct
13	Correct	2 ms	5464 KB	Output is correct
14	Correct	2 ms	5468 KB	Output is correct
15	Correct	1 ms	5468 KB	Output is correct
16	Correct	1 ms	5468 KB	Output is correct
17	Correct	1 ms	5464 KB	Output is correct
18	Correct	2 ms	5468 KB	Output is correct
19	Correct	1 ms	5468 KB	Output is correct
20	Correct	2 ms	5552 KB	Output is correct
21	Correct	2 ms	5468 KB	Output is correct
22	Correct	2 ms	5468 KB	Output is correct
23	Correct	1 ms	5468 KB	Output is correct
24	Correct	2 ms	5468 KB	Output is correct
25	Correct	2 ms	5464 KB	Output is correct
26	Correct	2 ms	5720 KB	Output is correct
27	Correct	2 ms	5468 KB	Output is correct
28	Correct	2 ms	5468 KB	Output is correct
29	Correct	2 ms	5468 KB	Output is correct
30	Correct	3 ms	5468 KB	Output is correct
31	Correct	2 ms	5468 KB	Output is correct
32	Correct	2 ms	5720 KB	Output is correct
33	Correct	5 ms	5720 KB	Output is correct
34	Correct	5 ms	5724 KB	Output is correct
35	Correct	19 ms	5724 KB	Output is correct
36	Correct	5 ms	5724 KB	Output is correct
37	Correct	6 ms	5724 KB	Output is correct
38	Correct	27 ms	5860 KB	Output is correct
39	Correct	7 ms	5724 KB	Output is correct
40	Correct	7 ms	5724 KB	Output is correct
41	Correct	33 ms	5724 KB	Output is correct
42	Correct	8 ms	5724 KB	Output is correct
43	Correct	8 ms	5860 KB	Output is correct
44	Correct	44 ms	5724 KB	Output is correct
45	Correct	9 ms	5724 KB	Output is correct
46	Correct	9 ms	5724 KB	Output is correct
47	Correct	54 ms	5980 KB	Output is correct
48	Correct	10 ms	5980 KB	Output is correct
49	Correct	11 ms	5980 KB	Output is correct
50	Correct	53 ms	5980 KB	Output is correct
51	Correct	11 ms	5980 KB	Output is correct
52	Correct	12 ms	5976 KB	Output is correct
53	Correct	69 ms	5980 KB	Output is correct
54	Correct	13 ms	5976 KB	Output is correct
55	Correct	14 ms	5980 KB	Output is correct
56	Correct	78 ms	5980 KB	Output is correct
57	Correct	15 ms	5980 KB	Output is correct
58	Correct	16 ms	5948 KB	Output is correct
59	Correct	102 ms	6232 KB	Output is correct
60	Correct	16 ms	5980 KB	Output is correct
61	Correct	25 ms	5988 KB	Output is correct
62	Correct	111 ms	6160 KB	Output is correct
63	Correct	77 ms	6140 KB	Output is correct
64	Correct	140 ms	5976 KB	Output is correct
65	Correct	112 ms	5980 KB	Output is correct
66	Correct	88 ms	5968 KB	Output is correct
67	Correct	84 ms	6144 KB	Output is correct
68	Correct	37 ms	6280 KB	Output is correct
69	Correct	35 ms	5976 KB	Output is correct
70	Correct	27 ms	5980 KB	Output is correct
71	Correct	31 ms	6028 KB	Output is correct
72	Correct	24 ms	5980 KB	Output is correct
73	Correct	39 ms	6812 KB	Output is correct
74	Correct	55 ms	6964 KB	Output is correct
75	Correct	66 ms	6972 KB	Output is correct
76	Correct	57 ms	6812 KB	Output is correct
77	Correct	57 ms	6748 KB	Output is correct
78	Correct	72 ms	7000 KB	Output is correct
79	Correct	46 ms	6740 KB	Output is correct
80	Correct	57 ms	6748 KB	Output is correct
81	Correct	65 ms	6884 KB	Output is correct
82	Correct	60 ms	6892 KB	Output is correct
83	Correct	74 ms	6624 KB	Output is correct
84	Correct	63 ms	6760 KB	Output is correct
85	Correct	69 ms	6740 KB	Output is correct
86	Correct	70 ms	6748 KB	Output is correct
87	Correct	70 ms	6696 KB	Output is correct
88	Correct	79 ms	6628 KB	Output is correct
89	Correct	73 ms	6480 KB	Output is correct
90	Correct	81 ms	6676 KB	Output is correct
91	Correct	74 ms	6480 KB	Output is correct
92	Correct	79 ms	6620 KB	Output is correct