/in/foo.cc: In function 'node* move(node*, short int)':
/in/foo.cc:24:13: warning: unused variable 'k' [-Wunused-variable]
   24 |         int k,i,j;
      |             ^
/in/foo.cc: At global scope:
/in/foo.cc:156:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  156 | main()
      | ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:159:30: warning: unused variable 'head2' [-Wunused-variable]
  159 |         node *head1,*tail1, *head2, *tail2;
      |                              ^~~~~
/in/foo.cc:159:38: warning: unused variable 'tail2' [-Wunused-variable]
  159 |         node *head1,*tail1, *head2, *tail2;
      |                                      ^~~~~
/in/foo.cc:162:34: warning: unused variable 'hash2' [-Wunused-variable]
  162 |         node_search_tree *hash1,*hash2;
      |                                  ^~~~~