foo.cc: In function 'void Process(int)':
foo.cc:96:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<fill.size(); i++) 
                ~^~~~~~~~~~~~
foo.cc:101:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<fill.size(); i++) 
                ~^~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:126:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while( s[k]!='-' && k<s.size() ) k++; 
                       ~^~~~~~~~~
foo.cc:127:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(k>=s.size()) break;
      ~^~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。