/in/foo.cc:12:12: warning: 'judgement' initialized and declared 'extern'
 extern int judgement=0;
            ^~~~~~~~~
/in/foo.cc: In function 'bool isInteger(char*)':
/in/foo.cc:84:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=1;i<len;i++)
                     ~^~~~
/in/foo.cc:89:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(k==len-1)
            ~^~~~~~~
/in/foo.cc:95:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<len;i++)
                     ~^~~~
/in/foo.cc:100:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(k==len)
            ~^~~~~