// Package binarysearchtree implements a binary search tree.
package binarysearchtree
// SearchTreeData represents an enrty in the tree.
type SearchTreeData struct {
	left  *SearchTreeData
	data  int
	right *SearchTreeData
}
// Bst creates a new binary search tree with input as the root node value.
func Bst(input int) *SearchTreeData {
	return &SearchTreeData{data: input}
}
// Insert inserts elem to the BST.
func (t *SearchTreeData) Insert(elem int) {
	if elem <= t.data {
		if t.left == nil {
			t.left = &SearchTreeData{data: elem}
			return
		}
		t.left.Insert(elem)
	} else {
		if t.right == nil {
			t.right = &SearchTreeData{data: elem}
			return
		}
		t.right.Insert(elem)
	}
}
func (t *SearchTreeData) MapString(f func(int) string) []string {
	var ret []string
	for _, elem := range t.inorder() {
		ret = append(ret, f(elem))
	}
	return ret
}
func (t *SearchTreeData) MapInt(f func(int) int) []int {
	var ret []int
	for _, elem := range t.inorder() {
		ret = append(ret, f(elem))
	}
	return ret
}
func (t *SearchTreeData) inorder() []int {
	ret := &[]int{}
	var recurse func(*SearchTreeData, *[]int)
	recurse = func(node *SearchTreeData, ret *[]int) {
		if node == nil {
			return
		}
		recurse(node.left, ret)
		*ret = append(*ret, node.data)
		recurse(node.right, ret)
	}
	recurse(t, ret)
	return *ret
}