foo.c: In function 'main':
foo.c:4:16: warning: unused variable 'j' [-Wunused-variable]
  int n,max=0,i,j;
                ^
foo.c:4:14: warning: unused variable 'i' [-Wunused-variable]
  int n,max=0,i,j;
              ^
foo.c:4:8: warning: unused variable 'max' [-Wunused-variable]
  int n,max=0,i,j;
        ^~~

自豪的采用jd5进行评测(github.com/masnn/jd5)