docs: add doc tree-zh-CN.md

docs/datastructure/tree.md

@@ -33,6 +33,7 @@ import (
 - [LevelOrderTraverse](#BSTree_LevelOrderTraverse)
 - [Depth](#BSTree_Depth)
 - [HasSubTree](#BSTree_HasSubTree)
+- [Print](#BSTree_Print)
 
 
 
@@ -413,6 +414,7 @@ func main() {
 	bstree.Insert(4)
 
     fmt.Println(bstree.Depth()) //4
+}
 ```
 
 
@@ -464,4 +466,62 @@ func main() {
 
     fmt.Println(superTree.HasSubTree(subTree)) //true
     fmt.Println(subTree.HasSubTree(superTree)) //false
+}
+```
+
+
+
+
+### <span id="BSTree_Print">Print</span>
+<p>Print the structure of binary saerch tree</p>
+
+<b>Signature:</b>
+
+```go
+func (t *BSTree[T]) Print()
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    tree "github.com/duke-git/lancet/v2/datastructure/tree"
+)
+
+type intComparator struct{}
+
+func (c *intComparator) Compare(v1, v2 any) int {
+	val1, _ := v1.(int)
+	val2, _ := v2.(int)
+
+	if val1 < val2 {
+		return -1
+	} else if val1 > val2 {
+		return 1
+	}
+	return 0
+}
+
+func main() {
+    bstree := tree.NewBSTree(6, &intComparator{})
+    bstree.Insert(7)
+	bstree.Insert(5)
+	bstree.Insert(2)
+	bstree.Insert(4)
+
+    fmt.Println(bstree.Print())
+//        6
+//       / \
+//      /   \
+//     /     \
+//    /       \
+//    5       7
+//   /
+//  /
+//  2
+//   \
+//    4
+}
 ```