BZOJ 2346 Lamp

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define maxn 550
#define inf 2000000000
using namespace std;
int n,m,map[maxn][maxn][5],dis[maxn][maxn];
int dx[]={0,-1,-1,1,1},dy[]={0,-1,1,1,-1};
queue <int> q;
bool vis[maxn][maxn];
char s[maxn];
bool judge(int x,int y)
{
    if ((x>=1) && (x<=n+1) && (y>=1) && (y<=m+1)) return true;
    return false;
}
void spfa()
{
    for (int i=1;i<=n+1;i++)
        for (int j=1;j<=m+1;j++)
            dis[i][j]=inf;
    dis[1][1]=0;q.push(1);q.push(1);vis[1][1]=true;
    while (!q.empty())
    {
        int hx,hy;
        hx=q.front();q.pop();hy=q.front();q.pop();
        for (int i=1;i<=4;i++)
        {
            int tx=hx+dx[i],ty=hy+dy[i];
            if ((judge(tx,ty)) && (dis[tx][ty]>dis[hx][hy]+map[hx][hy][i]))
            {
                dis[tx][ty]=dis[hx][hy]+map[hx][hy][i];
                if (!vis[tx][ty]) {q.push(tx);q.push(ty);vis[tx][ty]=true;}
            }
        }
        vis[hx][hy]=false;
    }
}
int main()
{
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++)
    {
        scanf("%s",s);
        for (int j=1;j<=m;j++)
        {
            if (s[j-1]==‘/‘) {map[i][j][3]=map[i+1][j+1][1]=1;map[i][j+1][4]=map[i+1][j][2]=0;}
            else {map[i][j+1][4]=map[i+1][j][2]=1;map[i][j][3]=map[i+1][j+1][1]=0;}
        }
    }
    spfa();
    if (dis[n+1][m+1]!=inf) printf("%d\n",dis[n+1][m+1]);
    else printf("NO SOLUTION\n");
    return 0;
}