/in/foo.cc: In function 'void add(char*)':
/in/foo.cc:11:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i < strlen(s);i++)
                   ~~^~~~~~~~~~~
/in/foo.cc: In function 'double getnum(char*)':
/in/foo.cc:29:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i < strlen(s);i++)
                   ~~^~~~~~~~~~~