Binary tree traversal - middle order traversal (golang)

brief introduction

In the sequence traversal （LDR） It's a kind of binary tree traversal , It's also called middle root traversal 、 Middle preface travels around .

Definition

In a binary tree , Middle order traversal first traverses the left subtree , Then access the root node , Finally, traverse the right subtree . If the binary tree is empty, it will return to , otherwise ：（1） The middle order traverses the left subtree （2） Access root （3） The middle order traverses the right subtree

As shown in the figure, binary tree , Middle order traversal result ：DBEAFC

Golang Realization

func (root *TreeNode) inorder()[]int{
    res:=[]int{}
    if root==nil{
        return res
    }
    stack:=[]*TreeNode{}
    for root!=nil || len(stack)!=0{
        if root!=nil{
            stack=append(stack,root)
            root=root.Lchild
        }else{
            root=stack[len(stack)-1]
            res=append(res,root.data)
            stack=stack[:len(stack)-1]
            root=root.Rchild
        }
    }
    return res
}