【USACO 2.4】The Tamworth Two

/*
TASK: ttwo
LANG: C++
*/
#include<cstdio>
#include<iostream>
char m[11][11];
int vis[101][101][5][5];
int dx[5]={-1,0,1,0},dy[5]={0,1,0,-1};
int ans;
bool ck(int x,int y){
    return x>=0&&x<10&&y>=0&&y<10&&m[x][y]!='*';
}
bool dfs(int fx,int fy,int df,int cx,int cy,int dc){
   // printf("f=(%d %d) %d c=(%d %d) %d\n",fx,fy,df,cx,cy,dc);
    int ff=fx*10+fy,cc=cx*10+cy;
    if(vis[ff][cc][df][dc])return 0;
    vis[ff][cc][df][dc]=1;
    if(ff==cc)
        return 1;
    ans++;
    int nfx=fx+dx[df],nfy=fy+dy[df],ncx=cx+dx[dc],ncy=cy+dy[dc];
    if(!ck(nfx,nfy)){
        df=(df+1)%4;
        nfx=fx;
        nfy=fy;
    }
    if(!ck(ncx,ncy)){
        dc=(dc+1)%4;
        ncx=cx;
        ncy=cy;
    }
    if(dfs(nfx,nfy,df,ncx,ncy,dc))return 1;
    ans--;
    return 0;
}
int main(){
    freopen("ttwo.in","r",stdin);
    freopen("ttwo.out","w",stdout);
    int cx,cy,fx,fy;
    for(int i=0;i<10;i++){
        scanf("%s",m[i]);
        for(int j=0;m[i][j];j++)
            if(m[i][j]=='C'){
                cx=i;
                cy=j;
            }else if(m[i][j]=='F'){
                fx=i;
                fy=j;
            }
    }
    if(dfs(fx,fy,0,cx,cy,0)){
        printf("%d\n",ans);
    }else{
        puts("0");
    }
    return 0;
}