/in/foo.cc:22:10: warning: multi-character character constant [-Wmultichar]
  ss[n-1]='/0';
          ^~~~
/in/foo.cc:23:27: warning: multi-character character constant [-Wmultichar]
  while (i < n && ss[i] != '/0'){
                           ^~~~
/in/foo.cc:25:28: warning: multi-character character constant [-Wmultichar]
   while (i < n && ss[i] != '/0'&& (ss[i] == ' ' || ss[i] == ',' || ss[i] == '.' ))
                            ^~~~
/in/foo.cc:27:28: warning: multi-character character constant [-Wmultichar]
   while (i < n && ss[i] != '/0'&& ss[i] != ' ' && ss[i] != ',' && ss[i] != '.'){
                            ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:22:10: warning: overflow in implicit constant conversion [-Woverflow]
  ss[n-1]='/0';
          ^~~~