/in/foo.cc: In function 'void built()':
/in/foo.cc:16:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<strlen(str1);i++)
                 ~^~~~~~~~~~~~~
/in/foo.cc: In function 'int query()':
/in/foo.cc:30:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0;i<strlen(str1);i++)
                ~^~~~~~~~~~~~~