foo.cc: In function 'int main()':
foo.cc:10:6: warning: unused variable 'n' [-Wunused-variable]
  int n=xmax-xmin+1;
      ^
foo.cc:10:12: warning: 'xmax' is used uninitialized in this function [-Wuninitialized]
  int n=xmax-xmin+1;
        ~~~~^~~~~
foo.cc:10:12: warning: 'xmin' is used uninitialized in this function [-Wuninitialized]
foo.cc:61:14: warning: array subscript is above array bounds [-Warray-bounds]
   if(max==c[9])
           ~~~^

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