/in/foo.cc: In function 'void DFS(int, int)':
/in/foo.cc:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int k=0;k<g[i].size();k++){
                 ~^~~~~~~~~~~~
/in/foo.cc:34:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int k=0;k<g[i].size();k++){
                 ~^~~~~~~~~~~~
/in/foo.cc:36:21: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if(j!=f && j!=x) dp[i][1]+=min(dp[j][0],dp[j][1]);
                    ~^~~