/in/foo.cc: In function 'int main()':
/in/foo.cc:10:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < strlen(str1); i++)
                  ~~^~~~~~~~~~~~~~
/in/foo.cc:60:3: warning: 'zs' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (zs)
   ^~