/in/foo.cc: In function 'void addNum(std::vector<Num>&, Num&)':
/in/foo.cc:137:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v.size();i++) {
                 ~^~~~~~~~~
/in/foo.cc: In function 'Num& getGoodOne(int, int)':
/in/foo.cc:201:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<vi.size();i++) {
                 ~^~~~~~~~~~
/in/foo.cc: In function 'void preCalc()':
/in/foo.cc:260:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int k=0;k<preBuild.size();k++) {
                         ~^~~~~~~~~~~~~~~~
/in/foo.cc:261:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 for(int k2=k+1;k2<preBuild.size();k2++) {
                                ~~^~~~~~~~~~~~~~~~