Tree

Given the `root` of a binary tree, return the level order traversal of its nodes' values.

Given the `root` of a binary tree, return the zigzag level order traversal of its nodes' values.

Given the `root` of a binary tree, determine if it is a valid binary search tree (BST).

Given the `root` of a binary tree, return the inorder traversal of its nodes' values.

Given the `root` of a binary tree, check whether it is a mirror of itself (i.

Write a function, maxPathSum, that takes in the root of a binary tree that contains number values.

Write a function, breadthFirstValues, that takes in the root of a binary tree.

Write a function, depthFirstValues, that takes in the root of a binary tree.

Write a function, treeIncludes, that takes in the root of a binary tree and a target value.

Write a function, treeSum, that takes in the root of a binary tree that contains number values.