/in/p2.cpp: In function 'opaque_list* unique(list_t)':
/in/p2.cpp:79:5: error: expected ',' or ';' before 'return'
     return list_make(d,ki);
     ^~~~~~
/in/p2.cpp:78:12: warning: unused variable 'ki' [-Wunused-variable]
     list_t ki=uniquen(list_rest(list),d)
            ^~
/in/p2.cpp:80:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/p2.cpp: In function 'opaque_list* insert_list(list_t, list_t, unsigned int)':
/in/p2.cpp:86:15: error: 'insert' was not declared in this scope
     list_t ki=insert(list_rest(first),second,n-1);
               ^~~~~~
/in/p2.cpp:86:15: note: suggested alternative: 'qsort'
     list_t ki=insert(list_rest(first),second,n-1);
               ^~~~~~
               qsort
/in/p2.cpp: In function 'opaque_list* chop(list_t, unsigned int)':
/in/p2.cpp:92:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(d<=n)return list_make();
        ~^~~
/in/p2.cpp: In function 'bool tree_search(tree_t, int)':
/in/p2.cpp:104:59: error: too few arguments to function 'bool tree_search(tree_t, int)'
     return tree_elt(tree)==val|tree_search(tree_left(tree))|tree_search(tree_right(tree));
                                                           ^
/in/p2.cpp:101:6: note: declared here
 bool tree_search(tree_t tree, int val)
      ^~~~~~~~~~~
/in/p2.cpp:104:89: error: too few arguments to function 'bool tree_search(tree_t, int)'
     return tree_elt(tree)==val|tree_search(tree_left(tree))|tree_search(tree_right(tree));
                                                                                         ^
/in/p2.cpp:101:6: note: declared here
 bool tree_search(tree_t tree, int val)
      ^~~~~~~~~~~
/in/p2.cpp: In function 'opaque_list* traversal(tree_t)':
/in/p2.cpp:123:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^