/in/foo.cc: In function 'int main()':
/in/foo.cc:18:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int kk=0;kk<f[j-w[i]].size();kk++)
                           ~~^~~~~~~~~~~~~~~~~
/in/foo.cc:20:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 if (f[j].size()<k)
                     ~~~~~~~~~~~^~
/in/foo.cc:36:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<f[v].size();i++) sum+=f[v][i];
              ~^~~~~~~~~~~~