/in/foo.cc: In function 'int kuaisu(int*, int*, int, int)':
/in/foo.cc:41:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int bu(int*, int*, int, int)':
/in/foo.cc:59:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^