/in/foo.cc: In function 'int main()':
/in/foo.cc:16:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i = 0; i < strlen(s); i++)
              ~~^~~~~~~~~~~
/in/foo.cc:19:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (j = i; j < i + strlen(t); j++)
               ~~^~~~~~~~~~~~~~~
/in/foo.cc:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (k = i; k < i + strlen(t); k++)
                ~~^~~~~~~~~~~~~~~