POJ 3009

#include<iostream>
#include<cstdio>
#include<cstring>
#define MAX 30 
using namespace std; 
int map[MAX][MAX]; 
const int dir[4][2]={-1, 0, 1, 0, 0, -1, 0, 1}; 
int h, w, ans; 
void dfs(int x, int y, int steps){
    if(steps > ans || steps > 10 || map[x][y] == -1)
        return; 
    for(int i = 0; i < 4; i ++){
        int xx = x; 
        int yy = y; 
        if(map[xx + dir[i][0]][yy + dir[i][1]] != 1){
            while(map[xx + dir[i][0]][yy + dir[i][1]] != 1){
                xx += dir[i][0]; 
                yy += dir[i][1]; 
                if(map[xx][yy] == -1)
                    break; 
                if(map[xx][yy] == 3){
                    if(ans > steps + 1) ans = steps + 1; 
                    return; 
                }
            }
            if(map[xx + dir[i][0]][yy + dir[i][1]] == 1){
                map[xx + dir[i][0]][yy + dir[i][1]] = 0; 
                dfs(xx, yy, steps + 1); 
                map[xx + dir[i][0]][yy + dir[i][1]] = 1; 
            }
        }
    }
}


int main(){
    int st, end; 
    /* freopen("in.c", "r", stdin); */ 
    while(cin >> w >> h && (h + w)){
        memset(map, -1, sizeof(map)); 
        for(int i = 1; i <= h; i ++){
            for(int j = 1; j <= w; j ++){
                cin >> map[i][j]; 
                if(map[i][j] == 2){
                    st = i; 
                    end = j; 
                }
            }
        }
        ans = 1 << 29; 
        dfs(st, end, 0); 
        if(ans > 10) ans = -1; 
        cout << ans << endl; 
    }
    return 0; 
}