/in/foo.cc: In function 'int dbfs(int, int)':
/in/foo.cc:20:41: warning: unused variable 'temp2' [-Wunused-variable]
  int head=0,head2=0,tail=1,tail2=1,temp,temp2;//head队头，tail队尾 
                                         ^~~~~
/in/foo.cc:70:14: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
      return x+que2[head2][2]+1;
             ~^~~~~~~~~~~~~~~
/in/foo.cc:48:25: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
      return que[head][2]+x+1;
             ~~~~~~~~~~~~^~