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답안 #763903

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
763903 2023-06-23T02:55:42 Z hanlulu Mecho (IOI09_mecho) C++14
38 / 100
 179 ms 6160 KB 
//https://cses.fi/problemset/task/1707
#include <bits/stdc++.h>
using namespace std; 
/*
有点像793的题目，两次最短。Bee走出到每一个位置的最短，
然后二分答案，然后Mecho走最短的时侯每一个相邻是否可以走需要计算是否Bee先到。
如何处理一分钟走s步这里？dis记录当前的步数，每次走到相邻+1，但是时间可以用dis/s得到。
注意：一个位置如果bee先到，比如2s到，m 3s到，那么m就不能走，如果相等可以走，因为每一次都是m先走。
但是，终点要特殊处理。 
*/
int n,s;
char a[801][801];
int rdir[4] = {0,0,1,-1};
int cdir[4] = {1,-1,0,0};
vector<vector<int>> beetime(801,vector<int>(801,1e9));

int sx,sy,ex,ey;//起点和终点 

bool isok(int eat)//eat is how many time he stay at start point. 
{
	vector<vector<int>> mstep(801,vector<int>(801,1e9));
	//cout << eat << endl;
	queue<pair<int,int>> myq;
	mstep[sx][sy] = 0;
	myq.push({sx,sy}); 
	while (!myq.empty()) {
		int x = myq.front().first;
		int y = myq.front().second;
		myq.pop();
		for (int i = 0; i < 4; i++)
		{
			int newx = x + rdir[i];
			int newy = y + cdir[i];
			if (a[newx][newy] == 'D') return true;//终点不需要判断了。因为bee到不了。 
			if (newx <0 || newx == n || newy < 0 || newy == n) continue;
			if (a[newx][newy] == 'T' || a[newx][newy] == 'H') continue;
			if (mstep[newx][newy] <= mstep[x][y] + 1) continue;
			if (beetime[newx][newy] < ceil(1.0*(mstep[x][y]+1) /s) + eat) continue; 
			//cout << newx << " " << newy << " " << (mstep[x][y]+1) /s + eat << endl;
			mstep[newx][newy] = mstep[x][y] + 1;
			
			myq.push({newx,newy});
		}		
	}
	//cout <<  mstep[2][2]  << endl;
	return false;
}
int main()
{
  	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	//freopen("nocross.in","r",stdin);
	//freopen("nocross.out","w",stdout);
 	cin >> n >> s;
	
	queue<pair<int,int>> myq;
 	for (int i = 0; i < n; i++) 
 	for (int j = 0; j < n; j++) 
 	{
 		cin >> a[i][j];
 		if (a[i][j] == 'M') sx = i, sy = j;
 		if (a[i][j] == 'D') ex = i, ey = j;
 		if (a[i][j] == 'H') {
 			beetime[i][j] = 0;
 			myq.push({i,j});
		};
	}	

  	//find beetime
	while (!myq.empty()) {
		int x = myq.front().first;
		int y = myq.front().second;
		myq.pop();
		for (int i = 0; i < 4; i++)
		{
			int newx = x + rdir[i];
			int newy = y + cdir[i];
			if (newx <0 || newx == n || newy < 0 || newy == n) continue;
			if (a[newx][newy] == 'T' ||  a[newx][newy] == 'H') continue;
			if (beetime[newx][newy] <= beetime[x][y] + 1) continue;
			
			beetime[newx][newy] = beetime[x][y] + 1;
			
			if (a[newx][newy] != 'D' )//can not go throuh home, but need know the time bee arrive
 				myq.push({newx,newy});
		}
	}
	  //	cout << beetime[2][2]<< endl;
  	//bin the answer
  	int ans = -1;
  	int l = 0, r =  n*n, mid;
  	while (l <= r) {
  		mid = (l+r)/2;
  		//cout << "mid " << mid <<  endl;
		if (isok(mid)) {
			ans = mid;
			l = mid + 1;
		}	
		else r = mid - 1;
	}
	cout << ans << '\n'; 
	return 0;
}

Subtask #1
38.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 5 ms 5432 KB Output isn't correct
2 Incorrect 4 ms 5392 KB Output isn't correct
3 Incorrect 5 ms 5412 KB Output isn't correct
4 Incorrect 5 ms 5412 KB Output isn't correct
5 Correct 7 ms 5432 KB Output is correct
6 Correct 6 ms 5428 KB Output is correct
7 Correct 107 ms 6100 KB Output is correct
8 Incorrect 7 ms 5472 KB Output isn't correct
9 Correct 7 ms 5472 KB Output is correct
10 Correct 6 ms 5472 KB Output is correct
11 Correct 6 ms 5440 KB Output is correct
12 Incorrect 9 ms 5472 KB Output isn't correct
13 Incorrect 8 ms 5500 KB Output isn't correct
14 Correct 9 ms 5476 KB Output is correct
15 Incorrect 7 ms 5452 KB Output isn't correct
16 Correct 9 ms 5432 KB Output is correct
17 Incorrect 9 ms 5452 KB Output isn't correct
18 Correct 8 ms 5452 KB Output is correct
19 Incorrect 8 ms 5464 KB Output isn't correct
20 Correct 7 ms 5456 KB Output is correct
21 Incorrect 9 ms 5472 KB Output isn't correct
22 Correct 11 ms 5472 KB Output is correct
23 Incorrect 11 ms 5472 KB Output isn't correct
24 Correct 8 ms 5516 KB Output is correct
25 Incorrect 10 ms 5532 KB Output isn't correct
26 Correct 9 ms 5532 KB Output is correct
27 Incorrect 9 ms 5472 KB Output isn't correct
28 Correct 10 ms 5492 KB Output is correct
29 Incorrect 10 ms 5532 KB Output isn't correct
30 Correct 10 ms 5532 KB Output is correct
31 Incorrect 10 ms 5508 KB Output isn't correct
32 Correct 10 ms 5504 KB Output is correct
33 Incorrect 13 ms 5736 KB Output isn't correct
34 Correct 14 ms 5740 KB Output is correct
35 Correct 41 ms 5736 KB Output is correct
36 Incorrect 20 ms 5780 KB Output isn't correct
37 Correct 15 ms 5780 KB Output is correct
38 Correct 42 ms 5744 KB Output is correct
39 Incorrect 18 ms 5808 KB Output isn't correct
40 Correct 16 ms 5808 KB Output is correct
41 Correct 53 ms 5792 KB Output is correct
42 Incorrect 17 ms 5848 KB Output isn't correct
43 Correct 17 ms 5856 KB Output is correct
44 Correct 66 ms 5836 KB Output is correct
45 Incorrect 23 ms 5888 KB Output isn't correct
46 Correct 18 ms 5872 KB Output is correct
47 Correct 71 ms 5880 KB Output is correct
48 Incorrect 19 ms 5948 KB Output isn't correct
49 Correct 21 ms 5940 KB Output is correct
50 Correct 86 ms 5892 KB Output is correct
51 Incorrect 21 ms 5948 KB Output isn't correct
52 Correct 21 ms 5952 KB Output is correct
53 Correct 104 ms 5964 KB Output is correct
54 Incorrect 21 ms 6076 KB Output isn't correct
55 Correct 21 ms 6084 KB Output is correct
56 Correct 118 ms 5984 KB Output is correct
57 Incorrect 23 ms 6056 KB Output isn't correct
58 Correct 24 ms 6104 KB Output is correct
59 Correct 132 ms 6028 KB Output is correct
60 Incorrect 28 ms 6088 KB Output isn't correct
61 Correct 24 ms 6076 KB Output is correct
62 Correct 153 ms 6100 KB Output is correct
63 Correct 106 ms 6052 KB Output is correct
64 Correct 179 ms 6056 KB Output is correct
65 Correct 141 ms 6060 KB Output is correct
66 Incorrect 124 ms 6104 KB Output isn't correct
67 Correct 110 ms 6068 KB Output is correct
68 Correct 55 ms 6092 KB Output is correct
69 Correct 50 ms 6108 KB Output is correct
70 Correct 41 ms 6092 KB Output is correct
71 Correct 46 ms 6080 KB Output is correct
72 Incorrect 36 ms 6096 KB Output isn't correct
73 Incorrect 49 ms 6156 KB Output isn't correct
74 Correct 70 ms 6084 KB Output is correct
75 Correct 89 ms 6064 KB Output is correct
76 Correct 82 ms 6096 KB Output is correct
77 Correct 76 ms 6056 KB Output is correct
78 Correct 95 ms 6100 KB Output is correct
79 Correct 57 ms 6156 KB Output is correct
80 Correct 72 ms 6096 KB Output is correct
81 Correct 104 ms 6160 KB Output is correct
82 Correct 73 ms 6116 KB Output is correct
83 Correct 106 ms 6056 KB Output is correct
84 Correct 87 ms 6116 KB Output is correct
85 Correct 99 ms 6136 KB Output is correct
86 Correct 91 ms 6084 KB Output is correct
87 Correct 97 ms 6060 KB Output is correct
88 Correct 99 ms 6092 KB Output is correct
89 Correct 102 ms 6088 KB Output is correct
90 Correct 113 ms 6080 KB Output is correct
91 Correct 101 ms 6100 KB Output is correct
92 Correct 109 ms 6076 KB Output is correct