답안 #948117

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
948117	2024-03-17T15:29:54 Z	packmani	Mecho (IOI09_mecho)	C++14	100 / 100	151 ms	7260 KB

mecho

#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;
	if(time>=board[s.first][s.second]) return 0;
	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};
				board[i][j]=1000000;
			}
			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]);
		}
	}
	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;
		
	}
	//printBoard();
	cout << ans;
}

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	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	4696 KB	Output is correct
5	Correct	1 ms	4696 KB	Output is correct
6	Correct	1 ms	4700 KB	Output is correct
7	Correct	57 ms	7004 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	4700 KB	Output is correct
11	Correct	1 ms	4700 KB	Output is correct
12	Correct	2 ms	4700 KB	Output is correct
13	Correct	1 ms	4700 KB	Output is correct
14	Correct	2 ms	4696 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	4700 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	4700 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	4700 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	4696 KB	Output is correct
33	Correct	4 ms	6744 KB	Output is correct
34	Correct	3 ms	6744 KB	Output is correct
35	Correct	14 ms	7000 KB	Output is correct
36	Correct	4 ms	6748 KB	Output is correct
37	Correct	4 ms	6620 KB	Output is correct
38	Correct	19 ms	6876 KB	Output is correct
39	Correct	5 ms	6748 KB	Output is correct
40	Correct	5 ms	6748 KB	Output is correct
41	Correct	27 ms	6804 KB	Output is correct
42	Correct	6 ms	6744 KB	Output is correct
43	Correct	6 ms	6748 KB	Output is correct
44	Correct	30 ms	6812 KB	Output is correct
45	Correct	7 ms	6748 KB	Output is correct
46	Correct	7 ms	6744 KB	Output is correct
47	Correct	36 ms	6744 KB	Output is correct
48	Correct	8 ms	6744 KB	Output is correct
49	Correct	8 ms	6748 KB	Output is correct
50	Correct	41 ms	6744 KB	Output is correct
51	Correct	9 ms	6612 KB	Output is correct
52	Correct	9 ms	6620 KB	Output is correct
53	Correct	50 ms	6788 KB	Output is correct
54	Correct	10 ms	6748 KB	Output is correct
55	Correct	15 ms	7004 KB	Output is correct
56	Correct	60 ms	6748 KB	Output is correct
57	Correct	12 ms	6748 KB	Output is correct
58	Correct	11 ms	6620 KB	Output is correct
59	Correct	69 ms	6748 KB	Output is correct
60	Correct	12 ms	6748 KB	Output is correct
61	Correct	13 ms	6748 KB	Output is correct
62	Correct	75 ms	6788 KB	Output is correct
63	Correct	86 ms	6748 KB	Output is correct
64	Correct	151 ms	6784 KB	Output is correct
65	Correct	115 ms	6788 KB	Output is correct
66	Correct	100 ms	6784 KB	Output is correct
67	Correct	90 ms	6624 KB	Output is correct
68	Correct	44 ms	6844 KB	Output is correct
69	Correct	41 ms	6748 KB	Output is correct
70	Correct	34 ms	6748 KB	Output is correct
71	Correct	36 ms	6748 KB	Output is correct
72	Correct	29 ms	6740 KB	Output is correct
73	Correct	26 ms	7260 KB	Output is correct
74	Correct	47 ms	7192 KB	Output is correct
75	Correct	47 ms	7248 KB	Output is correct
76	Correct	43 ms	7260 KB	Output is correct
77	Correct	48 ms	7260 KB	Output is correct
78	Correct	54 ms	7260 KB	Output is correct
79	Correct	35 ms	7112 KB	Output is correct
80	Correct	40 ms	7256 KB	Output is correct
81	Correct	47 ms	7252 KB	Output is correct
82	Correct	40 ms	7260 KB	Output is correct
83	Correct	52 ms	7000 KB	Output is correct
84	Correct	50 ms	7040 KB	Output is correct
85	Correct	53 ms	7200 KB	Output is correct
86	Correct	56 ms	7036 KB	Output is correct
87	Correct	50 ms	7200 KB	Output is correct
88	Correct	58 ms	7004 KB	Output is correct
89	Correct	60 ms	7100 KB	Output is correct
90	Correct	55 ms	7104 KB	Output is correct
91	Correct	60 ms	7248 KB	Output is correct
92	Correct	68 ms	7004 KB	Output is correct