Submission #948101

# Submission time Handle Problem Language Result Execution time Memory
948101 2024-03-17T15:17:00 Z packmani Mecho (IOI09_mecho) C++14
43 / 100
134 ms 7516 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;
void printBoard()
{
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			cout << board[i][j] << ' ';
		}
		cout << '\n';
	}
	cout << '\n';
}
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') 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]);
		}
	}
	//printBoard();
	//cout << maxTime;
	//b-search answer in range(0,maxTime)
	/*for(int i=0;i<=maxTime;i++)
		cout << i << ' ';
	cout << '\n';
	for(int i=0;i<=maxTime;i++)
		cout << bfs(i) << ' ';
	cout << '\n';*/
	l=0;
	r=maxTime;
	m = l + (r-l)/2;
	int best=-1;
	while(l<=r)
	{
		//cout << l << ' ' << r << ' ' << m << '\n';
		if(bfs(m)==1) 
		{
			l=m+1;
			best = max(best,m);
		}
		else r=m-1;
		m = l + (r+0.5-l)/2;

	}
	if(m==0 and bfs(0)==0) cout << -1;
	else cout << max(best,m);
}
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 4700 KB Output isn't correct
2 Incorrect 1 ms 4700 KB Output isn't correct
3 Incorrect 1 ms 4700 KB Output isn't correct
4 Incorrect 1 ms 4700 KB Output isn't correct
5 Correct 1 ms 4672 KB Output is correct
6 Correct 1 ms 4700 KB Output is correct
7 Correct 75 ms 7008 KB Output is correct
8 Incorrect 1 ms 4700 KB Output isn't correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Incorrect 1 ms 4700 KB Output isn't correct
14 Correct 1 ms 4700 KB Output is correct
15 Incorrect 1 ms 4700 KB Output isn't correct
16 Correct 1 ms 4700 KB Output is correct
17 Incorrect 1 ms 4696 KB Output isn't correct
18 Correct 1 ms 4696 KB Output is correct
19 Incorrect 1 ms 4700 KB Output isn't correct
20 Correct 2 ms 4696 KB Output is correct
21 Incorrect 1 ms 4700 KB Output isn't correct
22 Correct 1 ms 4696 KB Output is correct
23 Incorrect 1 ms 4700 KB Output isn't correct
24 Correct 1 ms 4700 KB Output is correct
25 Incorrect 1 ms 4700 KB Output isn't correct
26 Correct 1 ms 4700 KB Output is correct
27 Incorrect 1 ms 4700 KB Output isn't correct
28 Correct 1 ms 4700 KB Output is correct
29 Incorrect 1 ms 4700 KB Output isn't correct
30 Correct 1 ms 4700 KB Output is correct
31 Incorrect 1 ms 4700 KB Output isn't correct
32 Correct 1 ms 4700 KB Output is correct
33 Incorrect 4 ms 6748 KB Output isn't correct
34 Correct 3 ms 6748 KB Output is correct
35 Correct 19 ms 6748 KB Output is correct
36 Incorrect 5 ms 6748 KB Output isn't correct
37 Correct 4 ms 6748 KB Output is correct
38 Correct 18 ms 6800 KB Output is correct
39 Incorrect 5 ms 6748 KB Output isn't correct
40 Correct 6 ms 6748 KB Output is correct
41 Correct 24 ms 6808 KB Output is correct
42 Incorrect 6 ms 6748 KB Output isn't correct
43 Correct 6 ms 6748 KB Output is correct
44 Correct 32 ms 6804 KB Output is correct
45 Incorrect 7 ms 6748 KB Output isn't correct
46 Correct 7 ms 6748 KB Output is correct
47 Correct 41 ms 6784 KB Output is correct
48 Incorrect 8 ms 6748 KB Output isn't correct
49 Correct 8 ms 6620 KB Output is correct
50 Correct 49 ms 6788 KB Output is correct
51 Incorrect 9 ms 6748 KB Output isn't correct
52 Correct 9 ms 6620 KB Output is correct
53 Correct 55 ms 6784 KB Output is correct
54 Incorrect 11 ms 6748 KB Output isn't correct
55 Correct 10 ms 6748 KB Output is correct
56 Correct 95 ms 6748 KB Output is correct
57 Incorrect 11 ms 6744 KB Output isn't correct
58 Correct 11 ms 6748 KB Output is correct
59 Correct 97 ms 6624 KB Output is correct
60 Incorrect 12 ms 6744 KB Output isn't correct
61 Correct 12 ms 6996 KB Output is correct
62 Correct 77 ms 6748 KB Output is correct
63 Correct 92 ms 6780 KB Output is correct
64 Correct 134 ms 6616 KB Output is correct
65 Correct 133 ms 6748 KB Output is correct
66 Incorrect 100 ms 6784 KB Output isn't correct
67 Correct 98 ms 6748 KB Output is correct
68 Correct 42 ms 6740 KB Output is correct
69 Correct 32 ms 6740 KB Output is correct
70 Correct 33 ms 6748 KB Output is correct
71 Correct 30 ms 6736 KB Output is correct
72 Incorrect 27 ms 6744 KB Output isn't correct
73 Incorrect 48 ms 7160 KB Output isn't correct
74 Correct 46 ms 7224 KB Output is correct
75 Correct 54 ms 7256 KB Output is correct
76 Correct 42 ms 7260 KB Output is correct
77 Correct 45 ms 7328 KB Output is correct
78 Correct 53 ms 7260 KB Output is correct
79 Correct 34 ms 7148 KB Output is correct
80 Correct 42 ms 7512 KB Output is correct
81 Correct 59 ms 7516 KB Output is correct
82 Correct 38 ms 7256 KB Output is correct
83 Correct 58 ms 7000 KB Output is correct
84 Correct 50 ms 7000 KB Output is correct
85 Correct 47 ms 7000 KB Output is correct
86 Correct 65 ms 7424 KB Output is correct
87 Correct 51 ms 7004 KB Output is correct
88 Correct 61 ms 7004 KB Output is correct
89 Correct 60 ms 7004 KB Output is correct
90 Correct 59 ms 6996 KB Output is correct
91 Correct 56 ms 7000 KB Output is correct
92 Correct 65 ms 7428 KB Output is correct