ML Binary Search Tree

1)Define a function that returns a list of integers that we would get from a breadth-first traversal of a BST. Develop your answer by completing the definition below for bfirst. fun bfirst(tr) = let fun bf([], ans) = ____________ | bf(leaf::t, ans) = _____________________ | bf(node(v,t1,t2)::t, ans) = __________________ in bf(________,__________) end; 2)Problem 3. Consider the following depth-first (“in order”) traversal of a BST. fun dfirst(leaf) = [] | dfirst(node(v,t1,t2)) = dfirst(t1) @ [v] @ dfirst(t2); Following the strategy of bfirst, develop a tail-recursive version of dfirst, called dfirst2.