HDU1010

<!-- lang: cpp -->
#include<iostream>
using namespace std;
int map[9][9],dx,dy;
bool sou(int x,int y,int time)
{
    if(x==dx&&y==dy&&time==0)
        return true;
    else if(x==dx&&y==dy)
        return false;
    if(!map[x+1][y])
    {
        map[x][y]=1;
        if(sou(x+1,y,time-1))
            return true;
    }
    if(!map[x-1][y])
    {
        map[x][y]=1;
        if(sou(x-1,y,time-1))
            return true;
    }
    if(!map[x][y+1])
    {
        map[x][y]=1;
        if(sou(x,y+1,time-1))
            return true;
    }
    if(!map[x][y-1])
    {
        map[x][y]=1;
        if(sou(x,y-1,time-1))
            return true;
    }
    map[x][y]=0;
    return false;
}
int main()
{
    int n,m,t,i,j,sx,sy;
    char a;
    while(cin>>n>>m>>t)
    {
        if((!n)&&(!m)&&(!t))
            break;
        for(i=0;i<9;i++)
            for(j=0;j<9;j++)
                map[i][j]=1;
        for(i=1;i<=n;i++)
            for(j=1;j<=m;j++)
            {
                cin>>a;
                switch(a)
                {
                    case 'S':
                        map[i][j]=1;
                        sx=i;
                        sy=j;
                        break;
                    case 'D':
                        map[i][j]=0;
                        dx=i;
                        dy=j;
                        break;
                    case '.':
                        map[i][j]=0;
                }
            }
        if(sou(sx,sy,t))
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
    return 0;
}