[U]Cow Tours

簡單的類比題，如果是要找周期性的話，真不會啊~....

/*ID:sevenst4LANG:C++PROG:ttwo*/#include<stdio.h>using namespace std;char map[20][20];void rotate( int &x,int &y ){  int tx,ty;  tx=x;ty=y;  x=ty;  y=-tx;}int main(){ freopen( "ttwo.in","r",stdin ); freopen( "ttwo.out","w",stdout ); int xf,yf,xc,yc; for( int i=1;i<=10;i++ ) {    scanf( "%s",map[i]+1 );  for( int j=1;j<=10;j++ ) {     if( map[i][j]=='F' ){      xf=i,yf=j;          }   if( map[i][j]=='C' ){      xc=i,yc=j;        }   }} for( int i=0;i<12;i++ )  map[0][i]=map[i][0]=map[11][i]=map[i][11]='*';     int step=0;    int cx,cy,fx,fy;    cx=fx=-1;    cy=fy=0;    while( step<1000000 )    {    if( map[xc+cx][yc+cy]=='*' )        {   rotate(cx,cy); }   else   {   xc+=cx;yc+=cy;}   if( map[xf+fx][yf+fy]=='*' )   {   rotate(fx,fy); }   else   {   xf+=fx;yf+=fy; }   step++;   if( xc==xf && yc==yf )      break;    }    if( step<1000000 )    printf( "%d\n",step );    else    printf( "0\n" );    return 0;}