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Submission #597616

# Submission time Handle Problem Language Result Execution time Memory
597616 2022-07-16T11:54:02 Z l_reho Mecho (IOI09_mecho) C++14
100 / 100
 205 ms 4544 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' && V[nr][nc] != 'M') || 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 = 0;
	int high = P[sr][sc];
	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;
		
	}
	
	cout<<ans<<endl;
	
}

int main(){
	solve();
}

Compilation message

mecho.cpp: In function 'void solve()':
mecho.cpp:117:12: warning: 'dr' may be used uninitialized in this function [-Wmaybe-uninitialized]
  117 |   if(solver(sr, sc, dr, dc, mid)){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~
mecho.cpp:110:21: warning: 'sc' may be used uninitialized in this function [-Wmaybe-uninitialized]
  110 |  int high = P[sr][sc];
      |                     ^
mecho.cpp:110:17: warning: 'sr' may be used uninitialized in this function [-Wmaybe-uninitialized]
  110 |  int high = P[sr][sc];
      |                 ^
mecho.cpp:117:12: warning: 'dc' may be used uninitialized in this function [-Wmaybe-uninitialized]
  117 |   if(solver(sr, sc, dr, dc, mid)){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 93 ms 4160 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 1 ms 300 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 300 KB Output is correct
14 Correct 2 ms 212 KB Output is correct
15 Correct 1 ms 304 KB Output is correct
16 Correct 1 ms 300 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 1 ms 212 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 212 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 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 7 ms 1080 KB Output is correct
34 Correct 7 ms 1076 KB Output is correct
35 Correct 21 ms 1092 KB Output is correct
36 Correct 9 ms 1332 KB Output is correct
37 Correct 8 ms 1236 KB Output is correct
38 Correct 30 ms 1316 KB Output is correct
39 Correct 10 ms 1564 KB Output is correct
40 Correct 12 ms 1464 KB Output is correct
41 Correct 43 ms 1500 KB Output is correct
42 Correct 13 ms 1968 KB Output is correct
43 Correct 18 ms 1988 KB Output is correct
44 Correct 48 ms 1876 KB Output is correct
45 Correct 15 ms 2352 KB Output is correct
46 Correct 15 ms 2356 KB Output is correct
47 Correct 59 ms 2228 KB Output is correct
48 Correct 16 ms 2644 KB Output is correct
49 Correct 20 ms 2688 KB Output is correct
50 Correct 81 ms 2624 KB Output is correct
51 Correct 20 ms 3080 KB Output is correct
52 Correct 21 ms 3000 KB Output is correct
53 Correct 80 ms 2952 KB Output is correct
54 Correct 23 ms 3312 KB Output is correct
55 Correct 25 ms 3284 KB Output is correct
56 Correct 93 ms 3280 KB Output is correct
57 Correct 28 ms 3684 KB Output is correct
58 Correct 30 ms 3660 KB Output is correct
59 Correct 111 ms 3756 KB Output is correct
60 Correct 31 ms 3984 KB Output is correct
61 Correct 31 ms 3984 KB Output is correct
62 Correct 128 ms 4124 KB Output is correct
63 Correct 118 ms 4112 KB Output is correct
64 Correct 205 ms 4120 KB Output is correct
65 Correct 169 ms 4012 KB Output is correct
66 Correct 144 ms 4124 KB Output is correct
67 Correct 156 ms 4120 KB Output is correct
68 Correct 63 ms 4104 KB Output is correct
69 Correct 47 ms 4172 KB Output is correct
70 Correct 41 ms 4104 KB Output is correct
71 Correct 46 ms 4080 KB Output is correct
72 Correct 39 ms 4052 KB Output is correct
73 Correct 49 ms 4544 KB Output is correct
74 Correct 70 ms 4348 KB Output is correct
75 Correct 68 ms 4452 KB Output is correct
76 Correct 69 ms 4428 KB Output is correct
77 Correct 71 ms 4428 KB Output is correct
78 Correct 109 ms 4316 KB Output is correct
79 Correct 63 ms 4388 KB Output is correct
80 Correct 64 ms 4400 KB Output is correct
81 Correct 79 ms 4412 KB Output is correct
82 Correct 69 ms 4404 KB Output is correct
83 Correct 94 ms 4344 KB Output is correct
84 Correct 78 ms 4308 KB Output is correct
85 Correct 85 ms 4260 KB Output is correct
86 Correct 95 ms 4328 KB Output is correct
87 Correct 84 ms 4320 KB Output is correct
88 Correct 89 ms 4300 KB Output is correct
89 Correct 86 ms 4168 KB Output is correct
90 Correct 97 ms 4136 KB Output is correct
91 Correct 111 ms 4172 KB Output is correct
92 Correct 96 ms 4256 KB Output is correct