problem101

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101. Symmetric Tree (Easy)

Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).

 

Example 1:

Input: root = [1,2,2,3,4,4,3]
Output: true

Example 2:

Input: root = [1,2,2,null,3,null,3]
Output: false

 

Constraints:

• The number of nodes in the tree is in the range [1, 1000].
• -100 <= Node.val <= 100

 

Follow up: Could you solve it both recursively and iteratively?

Related Topics

[Tree] [Depth-first Search] [Breadth-first Search]

Documentation

Index

• type TreeNode

Types

type TreeNode

type TreeNode = kit.TreeNode

TreeNode - Definition for a binary tree node.