#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> first_biene;
pair<int,int> zuhause;
int s,n;
vector<vector<int>> dist;
bool erreichbar(int i, int j, int zeit){
vector<vector<int>> erreicht(n+2, vector<int>(n+2, 1e9));
queue<pair<int,int>> next;
next.push({i,j});
erreicht[i][j] = zeit*s;
while(!next.empty()){
int i1 = next.front().first, j1 = next.front().second;
//cout << i1 << " " << j1 << endl;
next.pop();
//cout << erreicht[i1][j1]+1 << " " << first_biene[i1][j1+1]*s << " " << erreicht[i1][j1+1] << endl;
if(i1+1==zuhause.first && j1 == zuhause.second) return true;
else if(i1==zuhause.first && j1+1 == zuhause.second) return true;
else if(i1-1==zuhause.first && j1 == zuhause.second) return true;
if(i1==zuhause.first && j1-1 == zuhause.second) return true;
if(erreicht[i1][j1]+1 < first_biene[i1][j1+1]*s && erreicht[i1][j1]+1<erreicht[i1][j1+1]){
erreicht[i1][j1+1] = erreicht[i1][j1]+1;
next.push({i1, j1+1});
}
if(erreicht[i1][j1]+1 < first_biene[i1][j1-1]*s && erreicht[i1][j1]+1<erreicht[i1][j1-1]){
erreicht[i1][j1-1] = erreicht[i1][j1]+1;
next.push({i1, j1-1});
}
if(erreicht[i1][j1]+1 < first_biene[i1+1][j1]*s && erreicht[i1][j1]+1<erreicht[i1+1][j1]){
erreicht[i1+1][j1] = erreicht[i1][j1]+1;
next.push({i1+1, j1});
}
if(erreicht[i1][j1]+1 < first_biene[i1-1][j1]*s && erreicht[i1][j1]+1<erreicht[i1-1][j1]){
erreicht[i1-1][j1] = erreicht[i1][j1]+1;
next.push({i1-1, j1});
}
}
/*for(vector<int> k: erreicht){
for(int h: k) cout << h << " ";
cout << endl;
}*/
return false;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
pair<int,int> start;
cin >> n >> s;
vector<vector<char>> karte(n+2, vector<char>(n+2, 'T'));
first_biene = vector<vector<int>>(n+2, vector<int>(n+2,-1));
queue<pair<int,pair<int,int>>> bienen;
for (int i = 1; i <= n; i++){
for(int j=1; j<=n; j++){
cin >> karte[i][j];
if(karte[i][j]=='M'){
start = {i,j};
karte[i][j] = 'G';
}else if(karte[i][j] == 'D') zuhause = {i,j};
else if(karte[i][j] == 'T'){
first_biene[i][j] = 0;
}else if(karte[i][j] == 'H'){
first_biene[i][j] = 0;
bienen.push({0,{i,j}});
}
}
}
while(!bienen.empty()){
int zeitpunkt = bienen.front().first;
int i = bienen.front().second.first, j = bienen.front().second.second;
//cout << zeitpunkt << " " << i << " " << j << endl;
bienen.pop();
if(karte[i][j-1]=='G' && (first_biene[i][j-1]==-1 || zeitpunkt+1<first_biene[i][j-1])){
///cout << " " << i << " " << j-1 << endl;
first_biene[i][j-1] = zeitpunkt+1;
bienen.push({zeitpunkt+1, {i,j-1}});
}
if(karte[i-1][j]=='G' && (zeitpunkt+1 < first_biene[i-1][j] || first_biene[i-1][j] == -1)){
//cout << " " << i-1 << " " << j << endl;
first_biene[i-1][j] = zeitpunkt+1;
bienen.push({zeitpunkt+1, {i-1, j}});
}
if(karte[i+1][j]=='G' && (zeitpunkt+1 < first_biene[i+1][j] || first_biene[i+1][j] == -1)){
//cout << " " << i+1 << " " << j << endl;
first_biene[i+1][j] = zeitpunkt+1;
bienen.push({zeitpunkt+1, {i+1,j}});
}
if(karte[i][j+1]=='G' && (zeitpunkt+1 < first_biene[i][j+1] || first_biene[i][j+1] == -1)){
//cout << " " << i << " " << j+1 << endl;
first_biene[i][j+1] = zeitpunkt+1;
bienen.push({zeitpunkt+1, {i, j+1}});
}
}
/*for (auto y : first_biene){
for (auto x : y){
cout << x << " ";
}
cout << endl;
}
*/
int lower = 0, upper = first_biene[start.first][start.second]-1;
while(lower<=upper){
int zeit = (upper+lower)/2;
//cout << "Zeit: " << zeit << endl;
dist = vector<vector<int>>(n+2, vector<int>(n+2, 1e9));
if(erreichbar(start.first, start.second, zeit)){
//cout << "erreicht: " << zeit << endl;
lower = zeit+1;
}else{//nicht erreichbar in Zeit
//cout << "nicht: " << zeit << endl;
upper = zeit-1;
}
//cout << endl;
}
//cout << lower << " " << upper << endl;
dist = vector<vector<int>>(n+2, vector<int>(n+2, 1e9));
if(lower == 0 && !erreichbar(start.first, start.second, 0)) cout << "-1" << endl;
else cout << lower-1;
return 0;
}
/*
-1 -1 -1 -1 -1 -1 -1 -1 -1
-1 0 0 0 0 0 0 0 -1
-1 0 5 5 5 5 5 0 -1
-1 0 4 4 4 4 4 0 -1
-1 4 3 3 3 3 3 -1 -1
-1 0 2 2 2 2 2 0 -1
-1 0 1 1 1 1 1 0 -1
-1 0 0 0 0 0 0 0 -1
-1 -1 -1 -1 -1 -1 -1 -1 -1
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
78 ms |
8620 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
0 ms |
212 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
1 ms |
340 KB |
Output is correct |
15 |
Correct |
1 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 |
340 KB |
Output is correct |
20 |
Correct |
0 ms |
212 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
0 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
340 KB |
Output is correct |
26 |
Correct |
1 ms |
340 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 |
1936 KB |
Output is correct |
34 |
Correct |
7 ms |
1936 KB |
Output is correct |
35 |
Correct |
14 ms |
1956 KB |
Output is correct |
36 |
Correct |
8 ms |
2388 KB |
Output is correct |
37 |
Correct |
9 ms |
2388 KB |
Output is correct |
38 |
Correct |
19 ms |
2440 KB |
Output is correct |
39 |
Correct |
11 ms |
2988 KB |
Output is correct |
40 |
Correct |
11 ms |
3044 KB |
Output is correct |
41 |
Correct |
23 ms |
2900 KB |
Output is correct |
42 |
Correct |
13 ms |
3588 KB |
Output is correct |
43 |
Correct |
14 ms |
3588 KB |
Output is correct |
44 |
Correct |
30 ms |
3540 KB |
Output is correct |
45 |
Correct |
16 ms |
4312 KB |
Output is correct |
46 |
Correct |
17 ms |
4280 KB |
Output is correct |
47 |
Correct |
36 ms |
4292 KB |
Output is correct |
48 |
Correct |
18 ms |
5008 KB |
Output is correct |
49 |
Correct |
19 ms |
5012 KB |
Output is correct |
50 |
Correct |
47 ms |
5000 KB |
Output is correct |
51 |
Correct |
22 ms |
5860 KB |
Output is correct |
52 |
Correct |
25 ms |
5888 KB |
Output is correct |
53 |
Correct |
51 ms |
5752 KB |
Output is correct |
54 |
Correct |
27 ms |
6724 KB |
Output is correct |
55 |
Correct |
27 ms |
6732 KB |
Output is correct |
56 |
Correct |
63 ms |
6696 KB |
Output is correct |
57 |
Correct |
31 ms |
7708 KB |
Output is correct |
58 |
Correct |
30 ms |
7636 KB |
Output is correct |
59 |
Correct |
76 ms |
7636 KB |
Output is correct |
60 |
Correct |
34 ms |
8648 KB |
Output is correct |
61 |
Correct |
35 ms |
8640 KB |
Output is correct |
62 |
Correct |
90 ms |
8592 KB |
Output is correct |
63 |
Correct |
101 ms |
8580 KB |
Output is correct |
64 |
Correct |
153 ms |
8520 KB |
Output is correct |
65 |
Correct |
155 ms |
8600 KB |
Output is correct |
66 |
Correct |
114 ms |
8604 KB |
Output is correct |
67 |
Correct |
117 ms |
8600 KB |
Output is correct |
68 |
Correct |
53 ms |
8608 KB |
Output is correct |
69 |
Correct |
51 ms |
8624 KB |
Output is correct |
70 |
Correct |
46 ms |
8672 KB |
Output is correct |
71 |
Correct |
43 ms |
8620 KB |
Output is correct |
72 |
Correct |
43 ms |
8644 KB |
Output is correct |
73 |
Correct |
35 ms |
8544 KB |
Output is correct |
74 |
Correct |
62 ms |
8628 KB |
Output is correct |
75 |
Correct |
63 ms |
8596 KB |
Output is correct |
76 |
Correct |
59 ms |
8624 KB |
Output is correct |
77 |
Correct |
65 ms |
8644 KB |
Output is correct |
78 |
Correct |
73 ms |
8628 KB |
Output is correct |
79 |
Correct |
57 ms |
8640 KB |
Output is correct |
80 |
Correct |
68 ms |
8728 KB |
Output is correct |
81 |
Correct |
64 ms |
8652 KB |
Output is correct |
82 |
Correct |
63 ms |
8644 KB |
Output is correct |
83 |
Correct |
72 ms |
8644 KB |
Output is correct |
84 |
Correct |
63 ms |
8624 KB |
Output is correct |
85 |
Correct |
63 ms |
8608 KB |
Output is correct |
86 |
Correct |
74 ms |
8624 KB |
Output is correct |
87 |
Correct |
62 ms |
8624 KB |
Output is correct |
88 |
Correct |
72 ms |
8632 KB |
Output is correct |
89 |
Correct |
68 ms |
8612 KB |
Output is correct |
90 |
Correct |
77 ms |
8632 KB |
Output is correct |
91 |
Correct |
77 ms |
8636 KB |
Output is correct |
92 |
Correct |
78 ms |
8608 KB |
Output is correct |