foo.cc: In function 'int Cin(int*, int)':
foo.cc:24:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cc: In function 'int maopao(int*, int)':
foo.cc:37:1: warning: no return statement in function returning non-void [-Wreturn-type]
 } 
 ^
foo.cc: In function 'int Output(int*, int)':
foo.cc:44:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cc: In function 'int main()':
foo.cc:9:9: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  int a[n],a1[n1];
         ^
foo.cc:9:16: warning: 'n1' is used uninitialized in this function [-Wuninitialized]
  int a[n],a1[n1];
                ^

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。