답안 #1099232

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1099232	2024-10-10T23:44:02 Z	ArtistWall	Mecho (IOI09_mecho)	C++17	100 / 100	464 ms	7512 KB

mecho

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

const int MAX_N = 800;
vector<string> field(MAX_N);
int n, s;

bool valid_sq(int x, int y) {
	return x >= 0 && x < n && y >= 0 && y < n &&
	       (field[x][y] == 'G' || field[x][y] == 'M');
}

bool mecho_reached(int mecho_dis, int bees_dis) { return mecho_dis / s < bees_dis; }

int main() {
	cin >> n >> s;
	for (int i = 0; i < n; i++) { cin >> field[i]; }

	vector<pair<int, int>> hives;
	int mechox, mechoy, home_x, home_y;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (field[i][j] == 'M') {
				mechox = i;
				mechoy = j;
			} else if (field[i][j] == 'H') {
				hives.push_back({i, j});
			} else if (field[i][j] == 'D') {
				home_x = i;
				home_y = j;
			}
		}
	}

	int dx[] = {-1, 0, 1, 0};
	int dy[] = {0, -1, 0, 1};
	int l = 0;
	int r = n * n;
	while (l <= r) {
		vector<vector<bool>> bees_visited(n, vector<bool>(n));
		vector<vector<bool>> mecho_visited(n, vector<bool>(n));
		vector<vector<int>> bees_time(n, vector<int>(n));
		vector<vector<int>> mecho_time(n, vector<int>(n));
		queue<pair<int, int>> q;

		int eating_time = (l + r) / 2;
		for (auto i : hives) {
			q.push({i.first, i.second});
			bees_visited[i.first][i.second] = true;
		}

		while (!q.empty()) {
			int x = q.front().first, y = q.front().second;
			q.pop();
			for (int i = 0; i < 4; i++) {
				int nx = x + dx[i], ny = y + dy[i];
				if (valid_sq(nx, ny) && !bees_visited[nx][ny]) {
					bees_time[nx][ny] = bees_time[x][y] + 1;
					q.push({nx, ny});
					bees_visited[nx][ny] = true;
				}
			}
		}
		q.push({mechox, mechoy});
		mecho_visited[mechox][mechoy] = true;
		if (bees_time[mechox][mechoy] <= eating_time) { q.pop(); }

		while (!q.empty()) {
			int x = q.front().first, y = q.front().second;
			q.pop();
			for (int i = 0; i < 4; i++) {
				int nx = x + dx[i], ny = y + dy[i];
				if (valid_sq(nx, ny) && !mecho_visited[nx][ny] &&
				    mecho_reached(mecho_time[x][y] + 1,
				                  bees_time[nx][ny] - eating_time)) {
					mecho_visited[nx][ny] = true;
					q.push({nx, ny});
					mecho_time[nx][ny] = mecho_time[x][y] + 1;
				}
			}
		}
		bool reached = false;
		for (int i = 0; i < 4; i++) {
			int nx = home_x + dx[i], ny = home_y + dy[i];
			if (valid_sq(nx, ny) &&
			    mecho_reached(mecho_time[nx][ny], bees_time[nx][ny] - eating_time) &&
			    mecho_visited[nx][ny]) {
				reached = true;
			}
		}
		if (reached) {
			l = eating_time + 1;
		} else {
			r = eating_time - 1;
		}
	}

	cout << l - 1 << '\n';
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:65:23: warning: 'mechox' may be used uninitialized in this function [-Wmaybe-uninitialized]
   65 |   mecho_visited[mechox][mechoy] = true;
      |                       ^
mecho.cpp:84:29: warning: 'home_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   84 |    int nx = home_x + dx[i], ny = home_y + dy[i];
      |                             ^~
mecho.cpp:84:8: warning: 'home_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   84 |    int nx = home_x + dx[i], ny = home_y + dy[i];
      |        ^~

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	348 KB	Output is correct
5	Correct	0 ms	348 KB	Output is correct
6	Correct	0 ms	388 KB	Output is correct
7	Correct	334 ms	7260 KB	Output is correct
8	Correct	0 ms	344 KB	Output is correct
9	Correct	0 ms	344 KB	Output is correct
10	Correct	1 ms	348 KB	Output is correct
11	Correct	0 ms	348 KB	Output is correct
12	Correct	1 ms	348 KB	Output is correct
13	Correct	1 ms	348 KB	Output is correct
14	Correct	2 ms	604 KB	Output is correct
15	Correct	1 ms	348 KB	Output is correct
16	Correct	0 ms	348 KB	Output is correct
17	Correct	1 ms	348 KB	Output is correct
18	Correct	1 ms	348 KB	Output is correct
19	Correct	0 ms	348 KB	Output is correct
20	Correct	1 ms	348 KB	Output is correct
21	Correct	1 ms	348 KB	Output is correct
22	Correct	1 ms	344 KB	Output is correct
23	Correct	1 ms	348 KB	Output is correct
24	Correct	1 ms	348 KB	Output is correct
25	Correct	1 ms	348 KB	Output is correct
26	Correct	1 ms	348 KB	Output is correct
27	Correct	1 ms	348 KB	Output is correct
28	Correct	1 ms	348 KB	Output is correct
29	Correct	1 ms	348 KB	Output is correct
30	Correct	1 ms	348 KB	Output is correct
31	Correct	1 ms	348 KB	Output is correct
32	Correct	1 ms	348 KB	Output is correct
33	Correct	30 ms	1828 KB	Output is correct
34	Correct	28 ms	1800 KB	Output is correct
35	Correct	48 ms	1784 KB	Output is correct
36	Correct	39 ms	2140 KB	Output is correct
37	Correct	38 ms	2136 KB	Output is correct
38	Correct	64 ms	2140 KB	Output is correct
39	Correct	46 ms	2608 KB	Output is correct
40	Correct	49 ms	2708 KB	Output is correct
41	Correct	83 ms	2396 KB	Output is correct
42	Correct	62 ms	3328 KB	Output is correct
43	Correct	60 ms	3432 KB	Output is correct
44	Correct	106 ms	3276 KB	Output is correct
45	Correct	79 ms	3832 KB	Output is correct
46	Correct	69 ms	3824 KB	Output is correct
47	Correct	123 ms	3672 KB	Output is correct
48	Correct	86 ms	4400 KB	Output is correct
49	Correct	87 ms	4412 KB	Output is correct
50	Correct	160 ms	4404 KB	Output is correct
51	Correct	104 ms	5016 KB	Output is correct
52	Correct	99 ms	5036 KB	Output is correct
53	Correct	194 ms	4952 KB	Output is correct
54	Correct	133 ms	5660 KB	Output is correct
55	Correct	116 ms	5704 KB	Output is correct
56	Correct	221 ms	5468 KB	Output is correct
57	Correct	143 ms	6400 KB	Output is correct
58	Correct	131 ms	6444 KB	Output is correct
59	Correct	247 ms	6380 KB	Output is correct
60	Correct	171 ms	7152 KB	Output is correct
61	Correct	150 ms	7172 KB	Output is correct
62	Correct	285 ms	7000 KB	Output is correct
63	Correct	379 ms	7148 KB	Output is correct
64	Correct	464 ms	7000 KB	Output is correct
65	Correct	426 ms	7108 KB	Output is correct
66	Correct	406 ms	7112 KB	Output is correct
67	Correct	380 ms	7000 KB	Output is correct
68	Correct	376 ms	7004 KB	Output is correct
69	Correct	369 ms	7004 KB	Output is correct
70	Correct	346 ms	7004 KB	Output is correct
71	Correct	361 ms	7000 KB	Output is correct
72	Correct	348 ms	7004 KB	Output is correct
73	Correct	306 ms	7260 KB	Output is correct
74	Correct	335 ms	7328 KB	Output is correct
75	Correct	353 ms	7436 KB	Output is correct
76	Correct	330 ms	7260 KB	Output is correct
77	Correct	338 ms	7436 KB	Output is correct
78	Correct	326 ms	7384 KB	Output is correct
79	Correct	306 ms	7260 KB	Output is correct
80	Correct	308 ms	7256 KB	Output is correct
81	Correct	335 ms	7260 KB	Output is correct
82	Correct	312 ms	7408 KB	Output is correct
83	Correct	345 ms	7260 KB	Output is correct
84	Correct	331 ms	7308 KB	Output is correct
85	Correct	347 ms	7512 KB	Output is correct
86	Correct	331 ms	7256 KB	Output is correct
87	Correct	330 ms	7260 KB	Output is correct
88	Correct	334 ms	7260 KB	Output is correct
89	Correct	345 ms	7260 KB	Output is correct
90	Correct	336 ms	7260 KB	Output is correct
91	Correct	338 ms	7316 KB	Output is correct
92	Correct	359 ms	7308 KB	Output is correct