Submission #948113

# Submission time Handle Problem Language Result Execution time Memory
948113 2024-03-17T15:24:55 Z packmani Mecho (IOI09_mecho) C++14
84 / 100
155 ms 7368 KB
#include<bits/stdc++.h>
using namespace std;
#define int long long int
int n,speed;
char inp[805][805];
int board[805][805];
bool visited[805][805];
queue<pair<int,int>> q;
pair<int,int> s,e;
int cr,cc,er,ec;
int dr[]={0,-1,0,1};
int dc[]={1,0,-1,0};
int maxTime=0;
int l,m,r;
int layer,tillNext,inNext;
bool bfs(int start)
{
	queue<pair<int,int>> tempq;
	memset(visited,0,sizeof(visited));
	int time=start;
	tempq.push({s.first,s.second});
	tillNext=1;
	inNext=0;
	layer=0;
	while(!tempq.empty())
	{
		cr = tempq.front().first;
		cc = tempq.front().second;
		tempq.pop();
		if(board[cr][cc]>time or inp[cr][cc]=='M')//bees have not reached this spot yet
		{
			//cout << time;
			for(int i=0;i<4;i++)
			{
				er = cr + dr[i];
				ec = cc + dc[i];
				if(er<0 or ec<0 or er>=n or ec>=n) continue;
				if(inp[er][ec]=='D') return 1;
				if(visited[er][ec]) continue;
				if(board[er][ec]==-1) continue;
				if(board[er][ec]<=time) continue;
				tempq.push({er,ec});
				visited[er][ec]=1;
				inNext++;
			}
		}
		tillNext--;
		if(tillNext==0)
		{
			tillNext = inNext;
			inNext = 0;
			layer++;
			if(layer%speed==0) time++;
		}
	}
	return 0;
}
int32_t main()
{
	cin.tie(0); ios_base::sync_with_stdio(false);
	cin >> n >> speed;
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			cin >> inp[i][j];
			if(inp[i][j]=='T') board[i][j]=-1; //no one can traverse
			if(inp[i][j]=='H') 
			{
				board[i][j]=0; //not walkable since the 0th sec
				q.push({i,j});
			}
			if(inp[i][j]=='M') s={i,j};
			if(inp[i][j]=='D') e={i,j};
			if(inp[i][j]=='G') board[i][j] = 1000000;
		}
	}
	//bees
	while(!q.empty())
	{
		cr = q.front().first;
		cc = q.front().second;
		q.pop();
		for(int i=0;i<4;i++)
		{
			er = cr + dr[i];
			ec = cc + dc[i];
			if(er<0 or ec<0 or er>=n or ec>=n) continue;
			if(board[er][ec]==-1 or board[er][ec]=='D' or board[er][ec]=='M' or board[er][ec]=='H') continue;
			if(board[er][ec]<=board[cr][cc]+1) continue;
			board[er][ec]=board[cr][cc]+1;
			q.push({er,ec});
			maxTime=max(maxTime,board[er][ec]);
		}
	}
	l=0;
	r=n*n;
	m = l + (r-l)/2;
	int ans=-1;
	while(l<=r)
	{
		//cout << l << ' ' << r << ' ' << m << '\n';
		m = l + (r+0.5-l)/2;
		if(bfs(m)==1) 
		{
			l=m+1;
			ans=m;
		}
		else r=m-1;
		
	}
	cout << ans;
}
# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4696 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4700 KB Output is correct
6 Correct 1 ms 4952 KB Output is correct
7 Correct 60 ms 6816 KB Output is correct
8 Correct 1 ms 4696 KB Output is correct
9 Correct 1 ms 4696 KB Output is correct
10 Correct 1 ms 4696 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Incorrect 1 ms 4700 KB Output isn't correct
13 Incorrect 1 ms 4700 KB Output isn't correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4700 KB Output is correct
16 Correct 1 ms 4700 KB Output is correct
17 Correct 1 ms 4700 KB Output is correct
18 Correct 1 ms 4700 KB Output is correct
19 Correct 1 ms 4696 KB Output is correct
20 Correct 1 ms 4700 KB Output is correct
21 Correct 1 ms 4700 KB Output is correct
22 Correct 1 ms 4700 KB Output is correct
23 Correct 1 ms 4696 KB Output is correct
24 Correct 1 ms 4700 KB Output is correct
25 Correct 1 ms 4700 KB Output is correct
26 Correct 1 ms 4700 KB Output is correct
27 Correct 1 ms 4700 KB Output is correct
28 Correct 1 ms 4700 KB Output is correct
29 Correct 1 ms 4740 KB Output is correct
30 Correct 1 ms 4700 KB Output is correct
31 Correct 1 ms 4700 KB Output is correct
32 Correct 1 ms 4700 KB Output is correct
33 Correct 3 ms 6748 KB Output is correct
34 Correct 4 ms 6616 KB Output is correct
35 Correct 15 ms 6748 KB Output is correct
36 Correct 4 ms 6744 KB Output is correct
37 Correct 5 ms 6744 KB Output is correct
38 Correct 21 ms 6620 KB Output is correct
39 Correct 5 ms 6744 KB Output is correct
40 Correct 5 ms 6748 KB Output is correct
41 Correct 24 ms 6612 KB Output is correct
42 Correct 6 ms 6744 KB Output is correct
43 Correct 6 ms 6748 KB Output is correct
44 Correct 33 ms 6748 KB Output is correct
45 Correct 7 ms 6744 KB Output is correct
46 Correct 7 ms 6748 KB Output is correct
47 Correct 38 ms 6748 KB Output is correct
48 Correct 8 ms 6748 KB Output is correct
49 Correct 9 ms 6620 KB Output is correct
50 Correct 42 ms 6636 KB Output is correct
51 Correct 9 ms 6748 KB Output is correct
52 Correct 9 ms 6744 KB Output is correct
53 Correct 51 ms 6744 KB Output is correct
54 Correct 10 ms 6748 KB Output is correct
55 Correct 10 ms 6748 KB Output is correct
56 Correct 60 ms 6748 KB Output is correct
57 Correct 12 ms 6748 KB Output is correct
58 Correct 12 ms 6800 KB Output is correct
59 Correct 72 ms 6748 KB Output is correct
60 Correct 13 ms 6748 KB Output is correct
61 Correct 13 ms 6616 KB Output is correct
62 Correct 100 ms 6788 KB Output is correct
63 Correct 84 ms 6784 KB Output is correct
64 Correct 155 ms 6744 KB Output is correct
65 Correct 113 ms 6616 KB Output is correct
66 Correct 98 ms 6996 KB Output is correct
67 Correct 90 ms 6780 KB Output is correct
68 Correct 42 ms 6844 KB Output is correct
69 Correct 45 ms 6736 KB Output is correct
70 Correct 36 ms 6672 KB Output is correct
71 Correct 43 ms 6864 KB Output is correct
72 Incorrect 31 ms 6736 KB Output isn't correct
73 Incorrect 49 ms 7260 KB Output isn't correct
74 Correct 42 ms 7280 KB Output is correct
75 Correct 55 ms 7332 KB Output is correct
76 Correct 48 ms 7344 KB Output is correct
77 Correct 49 ms 7352 KB Output is correct
78 Correct 54 ms 7368 KB Output is correct
79 Correct 38 ms 7248 KB Output is correct
80 Correct 42 ms 7256 KB Output is correct
81 Correct 50 ms 7112 KB Output is correct
82 Correct 42 ms 7248 KB Output is correct
83 Correct 56 ms 7004 KB Output is correct
84 Correct 48 ms 7000 KB Output is correct
85 Correct 51 ms 7196 KB Output is correct
86 Correct 53 ms 7000 KB Output is correct
87 Correct 56 ms 7284 KB Output is correct
88 Correct 57 ms 6996 KB Output is correct
89 Correct 54 ms 7004 KB Output is correct
90 Correct 60 ms 6996 KB Output is correct
91 Correct 59 ms 7100 KB Output is correct
92 Correct 65 ms 7004 KB Output is correct