treenode

Documentation

Overview

Package treenode provides a set of tools for writing LeetCode problems locally.

Index

• func ToSlice(root *TreeNode) []nilint.NilInt
• type TreeNode
  • func FromSlice(s []nilint.NilInt) *TreeNode

Functions

func ToSlice

func ToSlice(root *TreeNode) []nilint.NilInt

Convert the TreeNode into a slice.

For example, we have the root of a tree with type TreeNode, we can make a convertion like below:

ToSlice(root)

The output will be a slice. As is shown in all LeetCode problems, such as https://leetcode.com/problems/maximum-depth-of-binary-tree/.

Types

type TreeNode

type TreeNode struct {
	Val   int
	Left  *TreeNode
	Right *TreeNode
}

The TreeNode in this package can be used to declare the one in you package:

type TreeNode = treenode.TreeNode // type alias

func foo(root *TreeNode) {}

func FromSlice

func FromSlice(s []nilint.NilInt) *TreeNode

Create a TreeNode from a slice.

For example, a root is provided as a abstract slice which contains level scan result of a binary tree, refers to the problem Maximum Depth of Binary Tree: https://leetcode.com/problems/maximum-depth-of-binary-tree/.

We can follow the code below to create a TreeNode of root:

root := treenode.FromSlice([]nilint.NilInt{
    nilint.NewInt(3),
    nilint.NewInt(9),
    nilint.NewInt(20),
    nilint.NewNil(),
    nilint.NewNil(),
    nilint.NewInt(15),
    nilint.NewInt(7),
})

Explanation:

We cannot use []int as the type of the slice root because it contains null. We define a type nilint.NilInt to represent it, and now we can define the slice as type []nilint.NilInt. We provide function NewInt and NewNil to create integer and null value.

The function treenode.NewOperator returns an instance of type treenode.Operator with a lot of features. But in our case, we only need to get the root TreeNode we need from the method Root.