Submission #597575

# Submission time Handle Problem Language Result Execution time Memory
597575 2022-07-16T10:42:46 Z l_reho Mecho (IOI09_mecho) C++14
84 / 100
159 ms 4324 KB
#include <bits/stdc++.h>
using namespace std;

#define ll long long

int N, S;

vector<string> V;
vector<vector<int>> P;

int dirs[4][2] = {{1, 0},{0, 1},{-1, 0},{0, -1}};

struct info{
	int r, c, d;
	info(){}
	
	info(int _r, int _c, int _d): r(_r), c(_c), d(_d) {}
};

void precompute(vector<pair<int, int>> starts){
	
	queue<info> q;
	
	for(int i = 0; i < (int)starts.size(); i++){
		q.push(info(starts[i].first, starts[i].second, 0));
		P[starts[i].first][starts[i].second] = 0;
	}
	
	while(!q.empty()){
		info curr = q.front();
		q.pop();
		
		int r = curr.r;
		int c = curr.c;
		int depth = curr.d;
		
		for(int i = 0; i < 4; i++){
			int nr = r + dirs[i][0];
			int nc = c + dirs[i][1];
			
			if(nr < 0 || nr >= N || nc < 0 || nc >= N || V[nr][nc] != 'G' || P[nr][nc] != INT_MAX) continue;
			 
			P[nr][nc] = depth+1;
			
			q.push(info(nr, nc, depth+1));
			
		}
		
	}
	
	
}

bool solver(int r, int c, int dr, int dc, int l){
	
	queue<info> q;
	
	q.push(info(r, c, l+1));	
	vector<vector<bool>> visited(N, vector<bool>(N, false));
	
	while(!q.empty()){
		info curr = q.front();
		q.pop();
		
		int r = curr.r;
		int c = curr.c;
		int depth = curr.d;
			
		// cout<<"DEBUG-->"<<l<<" "<<r<<" "<<c<<endl;
		visited[r][c] = true;
		
		for(int i = 0; i < 4; i++){
			int nr = r + dirs[i][0];
			int nc = c + dirs[i][1];
			
			if(nr < 0 || nr >= N || nc < 0 || nc >= N || (V[nr][nc] != 'G' && V[nr][nc] != 'D') || visited[nr][nc] || P[nr][nc] <= (l + (int)((depth-l)/S))) continue;
	
			visited[nr][nc] = true;
	
			q.push(info(nr, nc, depth+1));
				
		}
		
	}
	
		
	return visited[dr][dc];
}

void solve(){
	cin>>N>>S;
	
	V.assign(N, "");
	P.assign(N, vector<int>(N, INT_MAX));
	
	vector<pair<int, int>> starts;
	int sr, sc, dr, dc;
	for(int i = 0; i < N; i++){
		cin>>V[i];
		for(int j = 0; j < N; j++) 
			if(V[i][j] == 'H') starts.push_back({i, j});
			else if(V[i][j] == 'M') sr = i, sc = j;
			else if(V[i][j] == 'D') dr = i, dc = j;
			
	}
	
	precompute(starts);

	int low = -1;
	int high = N*N;
	int ans = -1;

	while(low <= high){
		int mid = low + (high - low)/2;

		if(solver(sr, sc, dr, dc, mid)){
			ans = mid;
			low = mid+1;
		}else high = mid-1;
		
	}
	
	cout<<ans<<endl;
	
}

int main(){
	solve();
}

Compilation message

mecho.cpp: In function 'void solve()':
mecho.cpp:116:12: warning: 'sr' may be used uninitialized in this function [-Wmaybe-uninitialized]
  116 |   if(solver(sr, sc, dr, dc, mid)){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~
mecho.cpp:116:12: warning: 'dc' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:116:12: warning: 'dr' may be used uninitialized in this function [-Wmaybe-uninitialized]
mecho.cpp:116:12: warning: 'sc' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 276 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 108 ms 4052 KB Output is correct
8 Correct 0 ms 304 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Incorrect 1 ms 212 KB Output isn't correct
13 Incorrect 1 ms 212 KB Output isn't correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 1 ms 304 KB Output is correct
22 Correct 1 ms 212 KB Output is correct
23 Correct 1 ms 212 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 1 ms 212 KB Output is correct
26 Correct 1 ms 304 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 304 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 6 ms 1108 KB Output is correct
34 Correct 7 ms 1108 KB Output is correct
35 Correct 23 ms 1108 KB Output is correct
36 Correct 9 ms 1236 KB Output is correct
37 Correct 8 ms 1204 KB Output is correct
38 Correct 29 ms 1236 KB Output is correct
39 Correct 9 ms 1448 KB Output is correct
40 Correct 10 ms 1460 KB Output is correct
41 Correct 41 ms 1532 KB Output is correct
42 Correct 15 ms 2016 KB Output is correct
43 Correct 13 ms 1876 KB Output is correct
44 Correct 52 ms 2080 KB Output is correct
45 Correct 16 ms 2164 KB Output is correct
46 Correct 17 ms 2224 KB Output is correct
47 Correct 59 ms 2352 KB Output is correct
48 Correct 19 ms 2476 KB Output is correct
49 Correct 18 ms 2492 KB Output is correct
50 Correct 69 ms 2644 KB Output is correct
51 Correct 19 ms 2748 KB Output is correct
52 Correct 20 ms 2788 KB Output is correct
53 Correct 76 ms 2940 KB Output is correct
54 Correct 23 ms 3056 KB Output is correct
55 Correct 26 ms 3156 KB Output is correct
56 Correct 110 ms 3268 KB Output is correct
57 Correct 27 ms 3404 KB Output is correct
58 Correct 28 ms 3604 KB Output is correct
59 Correct 115 ms 3620 KB Output is correct
60 Correct 29 ms 3848 KB Output is correct
61 Correct 30 ms 3804 KB Output is correct
62 Correct 131 ms 3916 KB Output is correct
63 Correct 116 ms 3852 KB Output is correct
64 Correct 156 ms 3864 KB Output is correct
65 Correct 159 ms 3860 KB Output is correct
66 Correct 144 ms 3856 KB Output is correct
67 Correct 120 ms 3776 KB Output is correct
68 Correct 55 ms 3864 KB Output is correct
69 Correct 65 ms 3864 KB Output is correct
70 Correct 45 ms 3760 KB Output is correct
71 Correct 39 ms 3984 KB Output is correct
72 Incorrect 39 ms 3856 KB Output isn't correct
73 Incorrect 78 ms 4300 KB Output isn't correct
74 Correct 69 ms 4272 KB Output is correct
75 Correct 87 ms 4320 KB Output is correct
76 Correct 70 ms 4308 KB Output is correct
77 Correct 72 ms 4324 KB Output is correct
78 Correct 82 ms 4272 KB Output is correct
79 Correct 62 ms 4280 KB Output is correct
80 Correct 69 ms 4276 KB Output is correct
81 Correct 82 ms 4272 KB Output is correct
82 Correct 69 ms 4276 KB Output is correct
83 Correct 88 ms 4152 KB Output is correct
84 Correct 75 ms 4148 KB Output is correct
85 Correct 77 ms 4200 KB Output is correct
86 Correct 83 ms 4220 KB Output is correct
87 Correct 82 ms 4108 KB Output is correct
88 Correct 94 ms 4120 KB Output is correct
89 Correct 89 ms 4108 KB Output is correct
90 Correct 100 ms 4096 KB Output is correct
91 Correct 94 ms 3996 KB Output is correct
92 Correct 96 ms 4116 KB Output is correct