#include <bits/stdc++.h>
using namespace std;
#define inputJunk ios_base::sync_with_stdio(0); cin.tie(0);
#define pb push_back
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define debug cout<<"HERE"<<endl;
#define ell "\n"
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pi;
typedef pair<ll, ll> pll;
typedef pair<pi, int> trip;
typedef pair<pll, ll> tripll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
typedef vector<trip> vtrip;
const int INF = 1e9+1212;
const ll P = 9973, M = 1e9+9;
const int MM = 8e2+5; int mod = 1e9+7;//998244353
int n, k, sx, sy, ex, ey, dist[MM][MM]; char grid[MM][MM];
queue<pi> q; pi dir[4] {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
pi step[MM][MM];
bool vv(int a){
return a>=0&&a<n;
}
bool valid(int x, int y){
return vv(x)&&vv(y)&&(grid[x][y]=='G'||grid[x][y]=='M')&dist[x][y]==INF;
}
bool dfs(int t){
queue<pi> q;
for(int i = 0;i<n;i++){
for(int j = 0;j<n;j++){
step[i][j] = {-1, 0};
}
}
step[sx][sy] = {t, 0};
q.push({sx, sy});
while(!q.empty()){
int x = q.front().f, y = q.front().s; q.pop();
for(int i = 0;i<4;i++){
int newx = x+dir[i].f, newy = y+dir[i].s;
int newt = (step[x][y].s+1==k)?step[x][y].f+1:step[x][y].f;
int newused = (step[x][y].s+1)%k;
//cout<<newx<<" "<<newy<<endl;
if(vv(newx)&&vv(newy)&&(grid[newx][newy]=='G'||grid[newx][newy]=='D')&&newt<dist[newx][newy]&&step[newx][newy].f==-1){
step[newx][newy] = {newt, newused};
q.push({newx, newy});
}
}
}
//cout<<t<<ell;
/*
for(int i = 0;i<n;i++){
for(int j = 0;j<n;j++){
cout<<"("<<step[i][j].f<<" "<<step[i][j].s<<")"<<" ";
}cout<<ell;
}*/
return step[ex][ey].f!=-1;
}
int main(){
inputJunk
cin>>n>>k;
for(int i = 0;i<n;i++){
for(int j = 0;j<n;j++){
cin>>grid[i][j];
dist[i][j] = INF;
if(grid[i][j]=='M'){sx = i; sy = j;}
else if(grid[i][j]=='D'){ex = i;ey = j;}
else if(grid[i][j]=='H'){q.push({i, j}); dist[i][j] = 0;}
}
}
while(!q.empty()){
int curx = q.front().f, cury = q.front().s;q.pop();
//cout<<curx<<" "<<cury<<" "<<endl;
for(int i = 0;i<4;i++){
int newx = curx+dir[i].f, newy = cury+dir[i].s;
if(valid(newx, newy)){
dist[newx][newy] = dist[curx][cury]+1;
q.push({newx, newy});
}
}
}
/*
for(int i = 0;i<n;i++){
for(int j = 0;j<n;j++){
cout<<dist[i][j]<<" ";
}cout<<ell;
}*/
dist[ex][ey] = INF;
int lo = 0, hi = 10000000;
if(!dfs(0)){
cout<<-1<<endl;
return 0;
}
//cout<<"BOB"<<dfss(2)<<ell;
while(lo<hi){
//cout<<lo<<" "<<hi<<endl;
int mid = (lo+hi+1)/2;
if(mid<dist[sx][sy]&&dfs(mid)){
lo = mid;
}else{
hi = mid-1;
}
}
cout<<lo<<endl;
}
/*CUSTOM TEST CASE 1
*/
/*CUSTOM TEST CASE 2
*/
/*CUSTOM TEST CASE 3
*/
/*Comments of Shame
- floating error (use integer division instead)
- cin vs getline
- upperbound and lowerbound returns iteratorsf
- use long long when number is big enough
- for dp invalid cases needs to be skipped
- some base cases won't work (review cow poetry)
- always check bounds, some TLE are due to incorrect bounds!
- dont mess up return types
= RESET ARRAYS!!!!!!!!!!
- USE UR BRAIN
- INF setting problems
*/
/*
freopen("time.in","r", stdin);
freopen("time.out","w", stdout);
*/
Compilation message
mecho.cpp: In function 'bool valid(int, int)':
mecho.cpp:36:71: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
36 | return vv(x)&&vv(y)&&(grid[x][y]=='G'||grid[x][y]=='M')&dist[x][y]==INF;
| ~~~~~~~~~~^~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
332 KB |
Output is correct |
2 |
Correct |
0 ms |
332 KB |
Output is correct |
3 |
Correct |
0 ms |
332 KB |
Output is correct |
4 |
Correct |
0 ms |
332 KB |
Output is correct |
5 |
Correct |
1 ms |
332 KB |
Output is correct |
6 |
Correct |
0 ms |
332 KB |
Output is correct |
7 |
Correct |
131 ms |
8516 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
0 ms |
332 KB |
Output is correct |
10 |
Correct |
0 ms |
332 KB |
Output is correct |
11 |
Correct |
1 ms |
332 KB |
Output is correct |
12 |
Correct |
1 ms |
796 KB |
Output is correct |
13 |
Correct |
1 ms |
716 KB |
Output is correct |
14 |
Correct |
1 ms |
844 KB |
Output is correct |
15 |
Correct |
1 ms |
460 KB |
Output is correct |
16 |
Correct |
1 ms |
460 KB |
Output is correct |
17 |
Correct |
1 ms |
460 KB |
Output is correct |
18 |
Correct |
1 ms |
460 KB |
Output is correct |
19 |
Correct |
1 ms |
460 KB |
Output is correct |
20 |
Correct |
1 ms |
460 KB |
Output is correct |
21 |
Correct |
1 ms |
588 KB |
Output is correct |
22 |
Correct |
1 ms |
588 KB |
Output is correct |
23 |
Correct |
1 ms |
716 KB |
Output is correct |
24 |
Correct |
1 ms |
716 KB |
Output is correct |
25 |
Correct |
1 ms |
716 KB |
Output is correct |
26 |
Correct |
1 ms |
716 KB |
Output is correct |
27 |
Correct |
1 ms |
844 KB |
Output is correct |
28 |
Correct |
1 ms |
844 KB |
Output is correct |
29 |
Correct |
1 ms |
844 KB |
Output is correct |
30 |
Correct |
1 ms |
844 KB |
Output is correct |
31 |
Correct |
1 ms |
844 KB |
Output is correct |
32 |
Correct |
1 ms |
844 KB |
Output is correct |
33 |
Correct |
9 ms |
3896 KB |
Output is correct |
34 |
Correct |
11 ms |
3788 KB |
Output is correct |
35 |
Correct |
31 ms |
3788 KB |
Output is correct |
36 |
Correct |
10 ms |
4300 KB |
Output is correct |
37 |
Correct |
10 ms |
4332 KB |
Output is correct |
38 |
Correct |
41 ms |
4300 KB |
Output is correct |
39 |
Correct |
12 ms |
4912 KB |
Output is correct |
40 |
Correct |
14 ms |
4908 KB |
Output is correct |
41 |
Correct |
53 ms |
4812 KB |
Output is correct |
42 |
Correct |
16 ms |
5324 KB |
Output is correct |
43 |
Correct |
17 ms |
5440 KB |
Output is correct |
44 |
Correct |
65 ms |
5388 KB |
Output is correct |
45 |
Correct |
23 ms |
5944 KB |
Output is correct |
46 |
Correct |
24 ms |
5836 KB |
Output is correct |
47 |
Correct |
80 ms |
5848 KB |
Output is correct |
48 |
Correct |
21 ms |
6360 KB |
Output is correct |
49 |
Correct |
23 ms |
6404 KB |
Output is correct |
50 |
Correct |
96 ms |
6452 KB |
Output is correct |
51 |
Correct |
24 ms |
6908 KB |
Output is correct |
52 |
Correct |
30 ms |
6960 KB |
Output is correct |
53 |
Correct |
120 ms |
6872 KB |
Output is correct |
54 |
Correct |
37 ms |
7432 KB |
Output is correct |
55 |
Correct |
34 ms |
7436 KB |
Output is correct |
56 |
Correct |
156 ms |
7372 KB |
Output is correct |
57 |
Correct |
43 ms |
7980 KB |
Output is correct |
58 |
Correct |
40 ms |
7880 KB |
Output is correct |
59 |
Correct |
162 ms |
7988 KB |
Output is correct |
60 |
Correct |
35 ms |
8464 KB |
Output is correct |
61 |
Correct |
38 ms |
8468 KB |
Output is correct |
62 |
Correct |
188 ms |
8412 KB |
Output is correct |
63 |
Correct |
135 ms |
8504 KB |
Output is correct |
64 |
Correct |
206 ms |
8500 KB |
Output is correct |
65 |
Correct |
214 ms |
8388 KB |
Output is correct |
66 |
Correct |
169 ms |
8464 KB |
Output is correct |
67 |
Correct |
44 ms |
8388 KB |
Output is correct |
68 |
Correct |
67 ms |
8492 KB |
Output is correct |
69 |
Correct |
67 ms |
8476 KB |
Output is correct |
70 |
Correct |
65 ms |
8616 KB |
Output is correct |
71 |
Correct |
54 ms |
8516 KB |
Output is correct |
72 |
Correct |
44 ms |
8412 KB |
Output is correct |
73 |
Correct |
56 ms |
8740 KB |
Output is correct |
74 |
Correct |
110 ms |
8776 KB |
Output is correct |
75 |
Correct |
102 ms |
8772 KB |
Output is correct |
76 |
Correct |
102 ms |
8744 KB |
Output is correct |
77 |
Correct |
101 ms |
8736 KB |
Output is correct |
78 |
Correct |
45 ms |
8648 KB |
Output is correct |
79 |
Correct |
103 ms |
8672 KB |
Output is correct |
80 |
Correct |
93 ms |
8716 KB |
Output is correct |
81 |
Correct |
103 ms |
8804 KB |
Output is correct |
82 |
Correct |
99 ms |
8696 KB |
Output is correct |
83 |
Correct |
119 ms |
8712 KB |
Output is correct |
84 |
Correct |
123 ms |
8644 KB |
Output is correct |
85 |
Correct |
119 ms |
8712 KB |
Output is correct |
86 |
Correct |
119 ms |
8676 KB |
Output is correct |
87 |
Correct |
125 ms |
8708 KB |
Output is correct |
88 |
Correct |
130 ms |
8660 KB |
Output is correct |
89 |
Correct |
147 ms |
8660 KB |
Output is correct |
90 |
Correct |
139 ms |
8660 KB |
Output is correct |
91 |
Correct |
132 ms |
8648 KB |
Output is correct |
92 |
Correct |
125 ms |
8752 KB |
Output is correct |