Submission #815999

# Submission time Handle Problem Language Result Execution time Memory
815999 2023-08-09T03:36:17 Z powervic08 Mecho (IOI09_mecho) C++17
95 / 100
159 ms 6620 KB
#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) {
	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();
		minHiveDist[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 + S });
			}
		}
	}
}
 
void bfs2(int startR, int startC, int wait) {
	visited.clear(); visited.resize(N, vector<bool>(N));
	if (minHiveDist[startR][startC] <= wait * S) return;
	queue<pair<pii, int>> q; q.push({ {startR, startC}, wait * S });
	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 < 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[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;
}
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 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 67 ms 5152 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 Incorrect 1 ms 724 KB Output isn't correct
13 Correct 1 ms 596 KB Output is correct
14 Correct 1 ms 596 KB Output is correct
15 Correct 0 ms 340 KB Output is correct
16 Correct 1 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 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 2848 KB Output is correct
36 Correct 6 ms 2260 KB Output is correct
37 Correct 7 ms 2516 KB Output is correct
38 Correct 23 ms 3204 KB Output is correct
39 Correct 6 ms 2388 KB Output is correct
40 Correct 7 ms 2756 KB Output is correct
41 Correct 35 ms 3444 KB Output is correct
42 Correct 10 ms 2644 KB Output is correct
43 Correct 9 ms 3144 KB Output is correct
44 Correct 39 ms 3932 KB Output is correct
45 Correct 10 ms 2908 KB Output is correct
46 Correct 14 ms 3428 KB Output is correct
47 Correct 55 ms 4268 KB Output is correct
48 Correct 11 ms 3148 KB Output is correct
49 Correct 11 ms 3668 KB Output is correct
50 Correct 63 ms 4684 KB Output is correct
51 Correct 12 ms 3440 KB Output is correct
52 Correct 13 ms 3996 KB Output is correct
53 Correct 69 ms 5000 KB Output is correct
54 Correct 15 ms 3664 KB Output is correct
55 Correct 16 ms 4276 KB Output is correct
56 Correct 79 ms 5360 KB Output is correct
57 Correct 17 ms 3984 KB Output is correct
58 Correct 19 ms 4568 KB Output is correct
59 Correct 87 ms 5732 KB Output is correct
60 Correct 19 ms 4220 KB Output is correct
61 Correct 20 ms 4820 KB Output is correct
62 Correct 99 ms 6080 KB Output is correct
63 Correct 99 ms 6080 KB Output is correct
64 Correct 159 ms 6084 KB Output is correct
65 Correct 121 ms 6072 KB Output is correct
66 Correct 115 ms 6084 KB Output is correct
67 Correct 96 ms 6084 KB Output is correct
68 Correct 40 ms 6064 KB Output is correct
69 Correct 39 ms 6056 KB Output is correct
70 Correct 37 ms 6128 KB Output is correct
71 Correct 34 ms 6144 KB Output is correct
72 Correct 25 ms 4192 KB Output is correct
73 Correct 39 ms 6620 KB Output is correct
74 Correct 47 ms 6528 KB Output is correct
75 Correct 57 ms 6496 KB Output is correct
76 Correct 52 ms 6464 KB Output is correct
77 Correct 64 ms 6536 KB Output is correct
78 Correct 61 ms 5160 KB Output is correct
79 Correct 40 ms 4824 KB Output is correct
80 Correct 48 ms 4872 KB Output is correct
81 Correct 55 ms 4916 KB Output is correct
82 Correct 51 ms 5012 KB Output is correct
83 Correct 63 ms 5144 KB Output is correct
84 Correct 61 ms 5020 KB Output is correct
85 Correct 73 ms 5008 KB Output is correct
86 Correct 67 ms 5064 KB Output is correct
87 Correct 75 ms 5048 KB Output is correct
88 Correct 63 ms 5168 KB Output is correct
89 Correct 69 ms 5008 KB Output is correct
90 Correct 72 ms 5080 KB Output is correct
91 Correct 69 ms 5096 KB Output is correct
92 Correct 65 ms 5160 KB Output is correct