diff --git a/problems/0226.翻转二叉树.md b/problems/0226.翻转二叉树.md index b69cad55..fb5d831a 100644 --- a/problems/0226.翻转二叉树.md +++ b/problems/0226.翻转二叉树.md @@ -363,7 +363,9 @@ class Solution: return root ``` -### Go +### Go + +递归版本的前序遍历 ```Go func invertTree(root *TreeNode) *TreeNode { @@ -381,6 +383,96 @@ func invertTree(root *TreeNode) *TreeNode { } ``` +递归版本的后序遍历 + +```go +func invertTree(root *TreeNode) *TreeNode { + if root==nil{ + return root + } + invertTree(root.Left)//遍历左节点 + invertTree(root.Right)//遍历右节点 + root.Left,root.Right=root.Right,root.Left//交换 + return root +} +``` + +迭代版本的前序遍历 + +```go +func invertTree(root *TreeNode) *TreeNode { + stack:=[]*TreeNode{} + node:=root + for node!=nil||len(stack)>0{ + for node!=nil{ + node.Left,node.Right=node.Right,node.Left//交换 + stack=append(stack,node) + node=node.Left + } + node=stack[len(stack)-1] + stack=stack[:len(stack)-1] + node=node.Right + } + return root +} +``` + +迭代版本的后序遍历 + +```go +func invertTree(root *TreeNode) *TreeNode { + stack:=[]*TreeNode{} + node:=root + var prev *TreeNode + for node!=nil||len(stack)>0{ + for node!=nil{ + stack=append(stack,node) + node=node.Left + } + node=stack[len(stack)-1] + stack=stack[:len(stack)-1] + if node.Right==nil||node.Right==prev{ + node.Left,node.Right=node.Right,node.Left//交换 + prev=node + node=nil + }else { + stack=append(stack,node) + node=node.Right + } + } + return root +} +``` + +层序遍历 + +```go +func invertTree(root *TreeNode) *TreeNode { + if root==nil{ + return root + } + queue:=list.New() + node:=root + queue.PushBack(node) + for queue.Len()>0{ + length:=queue.Len() + for i:=0;i