/in/foo.cc: In function 'int main()':
/in/foo.cc:12:46: warning: array subscript has type 'char' [-Wchar-subscripts]
         if(c[n]>='a' && c[n]<='z')  dict[c[n]]++;
                                              ^
/in/foo.cc:17:19: warning: array subscript has type 'char' [-Wchar-subscripts]
         if (dict[m]<dict[i]) m=i; //ÕÒµ½ÒѼÓÃÜ×Ö´®ÖÐ×î¸ßƵ×Ö·û´æÓÚ m
                   ^
/in/foo.cc:17:27: warning: array subscript has type 'char' [-Wchar-subscripts]
         if (dict[m]<dict[i]) m=i; //ÕÒµ½ÒѼÓÃÜ×Ö´®ÖÐ×î¸ßƵ×Ö·û´æÓÚ m
                           ^