foo.cc: In function 'void Process(int)':
foo.cc:94:20: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if( !((isdigit(L) && isdigit(R) || islower(L) && islower(R)) && R>L) ) return;
         ~~~~~~~~~~~^~~~~~~~~~~~~
foo.cc:103:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<fill.size(); i++) 
                ~^~~~~~~~~~~~
foo.cc:108:17: 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:133:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while( s[k]!='-' && k<s.size() ) k++; 
                       ~^~~~~~~~~
foo.cc:134:7: 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。