/in/foo.cc: In function 'int main()':
/in/foo.cc:33:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<strlen(st);i++)
                ~^~~~~~~~~~~
/in/foo.cc:93:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while (j<strlen(str))
           ~^~~~~~~~~~~~
/in/foo.cc:119:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while (j<strlen(str))
           ~^~~~~~~~~~~~