foo.c: In function 'main':
foo.c:11:13: warning: array subscript has type 'char' [-Wchar-subscripts]
   s[j-1] = s[j];
             ^
foo.c:14:17: warning: array subscript has type 'char' [-Wchar-subscripts]
   printf("%c", s[i]);
                 ^

自豪的采用jd5进行评测(github.com/masnn/jd5)