foo.cc: In function 'int main()':
foo.cc:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0,j=j1;i<n&&k<v.size();k++,i++)
                         ~^~~~~~~~~
foo.cc:21:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0,j=j1;i<n&&k<v.size();k++,i++)
                         ~^~~~~~~~~

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