Submission #941732

# Submission time Handle Problem Language Result Execution time Memory
941732 2024-03-09T11:25:58 Z RavenHead Mecho (IOI09_mecho) C++17
100 / 100
146 ms 11420 KB
/*
	- Binary search by answer
	- BFS on all cells that Mecho can beat the bees to
*/

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

const int mxN=800;
int n, s, d1[mxN][mxN], d2[mxN][mxN], si, sj, ti, tj, lb=0, rb=mxN*mxN, nb[4][2]={{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
string g[mxN];
array<int, 2> qu[mxN*mxN];

void bfs(int d[mxN][mxN], int a) {
	int qt=0;
	for(int i=0; i<n; ++i)
		for(int j=0; j<n; ++j)
			if(!d[i][j])
				qu[qt++]={i, j};
	for(int i=0; i<qt; ++i) {
		array<int, 2> u=qu[i];
		if(a>=0&&d[u[0]][u[1]]/s+a>=d1[u[0]][u[1]])
			continue;
		for(int j=0; j<4; ++j) {
			int ni=u[0]+nb[j][0], nj=u[1]+nb[j][1];
			if(ni>=0&&ni<n&&nj>=0&&nj<n&&g[ni][nj]!='T'&&(a>=0||g[ni][nj]!='D')&&d[ni][nj]>1e7) {
				d[ni][nj]=d[u[0]][u[1]]+1;
				qu[qt++]={ni, nj};
			}
		}
	}
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> s;
	for(int i=0; i<n; ++i)
		cin >> g[i];
	memset(d1, 1, sizeof(d1));
	for(int i=0; i<n; ++i) {
		for(int j=0; j<n; ++j) {
			if(g[i][j]=='M') {
				si=i;
				sj=j;
			} else if(g[i][j]=='D') {
				ti=i;
				tj=j;
			} else if(g[i][j]=='H')
				d1[i][j]=0;
		}
	}
	bfs(d1, -1);
	while(lb<=rb) {
		int mb=(lb+rb)/2;
		memset(d2, 1, sizeof(d2));
		d2[si][sj]=0;
		bfs(d2, mb);
		if(d2[ti][tj]<1e7)
			lb=mb+1;
		else
			rb=mb-1;
	}
	cout << rb;
}
# Verdict Execution time Memory Grader output
1 Correct 3 ms 5976 KB Output is correct
2 Correct 3 ms 5980 KB Output is correct
3 Correct 3 ms 5980 KB Output is correct
4 Correct 4 ms 6136 KB Output is correct
5 Correct 2 ms 5980 KB Output is correct
6 Correct 3 ms 5980 KB Output is correct
7 Correct 71 ms 11164 KB Output is correct
8 Correct 2 ms 5980 KB Output is correct
9 Correct 3 ms 5980 KB Output is correct
10 Correct 2 ms 5980 KB Output is correct
11 Correct 3 ms 6232 KB Output is correct
12 Correct 2 ms 6236 KB Output is correct
13 Correct 3 ms 6236 KB Output is correct
14 Correct 3 ms 6248 KB Output is correct
15 Correct 3 ms 5980 KB Output is correct
16 Correct 3 ms 5980 KB Output is correct
17 Correct 2 ms 5980 KB Output is correct
18 Correct 2 ms 5976 KB Output is correct
19 Correct 2 ms 5980 KB Output is correct
20 Correct 2 ms 5980 KB Output is correct
21 Correct 3 ms 5980 KB Output is correct
22 Correct 2 ms 6232 KB Output is correct
23 Correct 2 ms 6080 KB Output is correct
24 Correct 3 ms 5976 KB Output is correct
25 Correct 4 ms 6488 KB Output is correct
26 Correct 3 ms 6236 KB Output is correct
27 Correct 3 ms 6236 KB Output is correct
28 Correct 3 ms 6232 KB Output is correct
29 Correct 3 ms 6236 KB Output is correct
30 Correct 2 ms 6236 KB Output is correct
31 Correct 2 ms 6236 KB Output is correct
32 Correct 2 ms 6236 KB Output is correct
33 Correct 6 ms 8540 KB Output is correct
34 Correct 6 ms 8540 KB Output is correct
35 Correct 16 ms 8572 KB Output is correct
36 Correct 7 ms 8536 KB Output is correct
37 Correct 7 ms 8540 KB Output is correct
38 Correct 20 ms 8612 KB Output is correct
39 Correct 8 ms 8540 KB Output is correct
40 Correct 8 ms 8540 KB Output is correct
41 Correct 26 ms 8660 KB Output is correct
42 Correct 9 ms 8536 KB Output is correct
43 Correct 11 ms 8540 KB Output is correct
44 Correct 38 ms 8540 KB Output is correct
45 Correct 10 ms 8792 KB Output is correct
46 Correct 11 ms 8540 KB Output is correct
47 Correct 40 ms 8540 KB Output is correct
48 Correct 11 ms 8792 KB Output is correct
49 Correct 11 ms 8824 KB Output is correct
50 Correct 52 ms 8796 KB Output is correct
51 Correct 14 ms 8792 KB Output is correct
52 Correct 16 ms 8792 KB Output is correct
53 Correct 54 ms 10840 KB Output is correct
54 Correct 15 ms 9048 KB Output is correct
55 Correct 15 ms 8796 KB Output is correct
56 Correct 62 ms 10992 KB Output is correct
57 Correct 17 ms 8792 KB Output is correct
58 Correct 18 ms 8796 KB Output is correct
59 Correct 90 ms 11072 KB Output is correct
60 Correct 20 ms 11096 KB Output is correct
61 Correct 21 ms 11100 KB Output is correct
62 Correct 94 ms 11144 KB Output is correct
63 Correct 79 ms 11144 KB Output is correct
64 Correct 146 ms 11096 KB Output is correct
65 Correct 112 ms 11148 KB Output is correct
66 Correct 100 ms 11144 KB Output is correct
67 Correct 87 ms 11096 KB Output is correct
68 Correct 42 ms 11096 KB Output is correct
69 Correct 40 ms 11160 KB Output is correct
70 Correct 32 ms 11096 KB Output is correct
71 Correct 37 ms 11096 KB Output is correct
72 Correct 27 ms 11168 KB Output is correct
73 Correct 28 ms 11096 KB Output is correct
74 Correct 55 ms 11160 KB Output is correct
75 Correct 53 ms 11420 KB Output is correct
76 Correct 44 ms 11148 KB Output is correct
77 Correct 45 ms 11100 KB Output is correct
78 Correct 72 ms 11096 KB Output is correct
79 Correct 37 ms 11100 KB Output is correct
80 Correct 44 ms 11100 KB Output is correct
81 Correct 52 ms 11100 KB Output is correct
82 Correct 45 ms 11148 KB Output is correct
83 Correct 58 ms 11100 KB Output is correct
84 Correct 52 ms 11156 KB Output is correct
85 Correct 63 ms 11100 KB Output is correct
86 Correct 53 ms 11100 KB Output is correct
87 Correct 60 ms 11096 KB Output is correct
88 Correct 62 ms 11100 KB Output is correct
89 Correct 74 ms 11096 KB Output is correct
90 Correct 63 ms 11100 KB Output is correct
91 Correct 57 ms 11144 KB Output is correct
92 Correct 63 ms 11100 KB Output is correct