From cf6ec4f65a8ee43a15c29f0a380cfac5f809a8dd Mon Sep 17 00:00:00 2001
From: X-shuffle <53906918+X-shuffle@users.noreply.github.com>
Date: Tue, 18 May 2021 22:58:00 +0800
Subject: [PATCH] =?UTF-8?q?Update=20=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84?=
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添加 二叉树的迭代遍历 GO版本
---
 problems/二叉树的迭代遍历.md | 102 +++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/problems/二叉树的迭代遍历.md b/problems/二叉树的迭代遍历.md
index 2647616b..d228077b 100644
--- a/problems/二叉树的迭代遍历.md
+++ b/problems/二叉树的迭代遍历.md
@@ -163,7 +163,109 @@ Python：
 
 
 Go：
+> 迭代法前序遍历
 
+```go
+//迭代法前序遍历
+/**
+ type Element struct {
+    // 元素保管的值
+    Value interface{}
+    // 内含隐藏或非导出字段
+}
+
+func (l *List) Back() *Element 
+前序遍历：中左右
+压栈顺序：右左中
+ **/
+func preorderTraversal(root *TreeNode) []int {
+	if root == nil {
+		return nil
+	}
+	var stack = list.New()
+    stack.PushBack(root.Right)
+    stack.PushBack(root.Left)
+    res:=[]int{}
+    res=append(res,root.Val)
+    for stack.Len()>0 {
+        e:=stack.Back()
+        stack.Remove(e)
+        node := e.Value.(*TreeNode)//e是Element类型，其值为e.Value.由于Value为接口，所以要断言
+        if node==nil{
+            continue
+        }
+        res=append(res,node.Val)
+        stack.PushBack(node.Right)
+        stack.PushBack(node.Left)
+    }
+    return res
+}
+```
+
+> 迭代法后序遍历
+
+```go
+//后续遍历：左右中
+//压栈顺序：中右左(按照前序遍历思路)，再反转结果数组
+func postorderTraversal(root *TreeNode) []int {
+	if root == nil {
+		return nil
+	}
+	var stack = list.New()
+    stack.PushBack(root.Left)
+    stack.PushBack(root.Right)
+    res:=[]int{}
+    res=append(res,root.Val)
+    for stack.Len()>0 {
+        e:=stack.Back()
+        stack.Remove(e)
+        node := e.Value.(*TreeNode)//e是Element类型，其值为e.Value.由于Value为接口，所以要断言
+        if node==nil{
+            continue
+        }
+        res=append(res,node.Val)
+        stack.PushBack(node.Left)
+        stack.PushBack(node.Right)
+    }
+    for i:=0;i<len(res)/2;i++{
+        res[i],res[len(res)-i-1] = res[len(res)-i-1],res[i]
+    }
+    return res
+}
+```
+
+> 迭代法中序遍历
+
+```go
+//迭代法中序遍历
+func inorderTraversal(root *TreeNode) []int {
+    rootRes:=[]int{}
+    if root==nil{
+       return nil
+    }
+    stack:=list.New()
+    node:=root
+    //先将所有左节点找到，加入栈中
+    for node!=nil{
+        stack.PushBack(node)
+        node=node.Left
+    }
+    //其次对栈中的每个节点先弹出加入到结果集中，再找到该节点的右节点的所有左节点加入栈中
+    for stack.Len()>0{
+        e:=stack.Back()
+        node:=e.Value.(*TreeNode)
+        stack.Remove(e)
+        //找到该节点的右节点，再搜索他的所有左节点加入栈中
+        rootRes=append(rootRes,node.Val)
+        node=node.Right
+        for node!=nil{
+            stack.PushBack(node)
+            node=node.Left
+        }
+    }
+    return rootRes
+}
+```