1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
| #include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <algorithm>
#include <queue>
#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<30
using namespace std;
typedef long long ll;
int w,h,x,y;
int sx,sy,gx,gy;
int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
int ans = 0;
bool f[25][25];
bool can(int y,int x) {
if(0 <= y && y < h && 0 <= x && x < w) return true;
return false;
}
void dfs(int y, int x, int cnt) {
if(cnt >= 10) return;
rep(i, 4) {
int ny = y;
int nx = x;
bool flag = false;
while(can(ny + dy[i], nx + dx[i]) && f[ny + dy[i]][nx + dx[i]]) {
ny += dy[i];
nx += dx[i];
if(ny == gy && nx == gx) {
flag = true;
break;
}
}
if(flag) {
ans = min(ans, cnt + 1);
return;
}
if(ny == y && nx == x) continue;
if(!can(ny + dy[i], nx + dx[i])) continue;
f[ny + dy[i]][nx + dx[i]] = true;
dfs(ny, nx, cnt + 1);
f[ny + dy[i]][nx + dx[i]] = false;
}
}
int main() {
while(cin >> w >> h) {
if(w == 0 && h == 0) break;
memset(f, 0, sizeof(f));
ans = INF;
rep(i, h) {
rep(j, w) {
int x;
cin >> x;
if(x == 0) f[i][j] = true;
if(x == 2) {
sy = i;
sx = j;
f[i][j] = true;
}
if(x == 3) {
gy = i;
gx = j;
f[i][j] = true;
}
}
}
dfs(sy, sx, 0);
if(ans == INF) cout << -1 << endl;
else cout << ans << endl;
}
return 0;
}
|