feat: add funcs to traverse bstree

datastructure/tree/bstree.go

@@ -10,7 +10,7 @@ import (
 // BSTree is a binary search tree data structure in which each node has at most two children,
 // which are referred to as the left child and the right child.
 // In BSTree: leftNode < rootNode < rightNode
-// type T should implments Compare function of lancetconstraints.Comparator interface
+// type T should implements Compare function in lancetconstraints.Comparator interface.
 type BSTree[T any] struct {
 	root *datastructure.TreeNode[T]
 }
@@ -43,6 +43,21 @@ func (t *BSTree[T]) NodeLevel(node *datastructure.TreeNode[T]) int {
 	return int(math.Max(left, right)) + 1
 }
 
+// PreOrderTraverse traverse tree node in pre order
+func (t *BSTree[T]) PreOrderTraverse() []T {
+	return preOrderTraverse(t.root)
+}
+
+// PostOrderTraverse traverse tree node in post order
+func (t *BSTree[T]) PostOrderTraverse() []T {
+	return postOrderTraverse(t.root)
+}
+
+// InOrderTraverse traverse tree node in mid order
+func (t *BSTree[T]) InOrderTraverse() []T {
+	return inOrderTraverse(t.root)
+}
+
 // Print the bstree structure
 func (t *BSTree[T]) Print() {
 	maxLevel := t.NodeLevel(t.root)