/in/foo.cc: In function 'int bfs()':
/in/foo.cc:46:11: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
           if(nx==x2 && ny==y2) //到达目的地 
           ^~
/in/foo.cc:49:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
     nx += dir[i][0];
     ^~
/in/foo.cc:54:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^