/in/foo.cc: In member function 'PloyListNode PloyListNode::operator+(PloyListNode)':
/in/foo.cc:17:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<node.size();i++)
                ~^~~~~~~~~~~~
/in/foo.cc:19:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<p.node.size();i++){
                ~^~~~~~~~~~~~~~
/in/foo.cc:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j=0;j<newv.size();j++){
                 ~^~~~~~~~~~~~
/in/foo.cc: In member function 'int PloyListNode::out(int)':
/in/foo.cc:41:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<node.size();i++)
                ~^~~~~~~~~~~~
/in/foo.cc: In function 'std::ostream& operator<<(std::ostream&, PloyListNode)':
/in/foo.cc:50:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<p.node.size();i++)
               ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:60:22: warning: unused variable 'x' [-Wunused-variable]
  int n,m;int a,b;int x;
                      ^