101.对称二叉树.go

/*
 * @lc app=leetcode.cn id=101 lang=golang
 *
 * [101] 对称二叉树
 */

// @lc code=start
/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func isSymmetric(root *TreeNode) bool {
	if root == nil {
		return false
	}

	return check(root, root)
}

func check(node1, node2 *TreeNode) bool {
	if node1 == nil && node2 == nil {
		return true
	}
	if node1 == nil || node2 == nil {
		return false
	}
	return node1.Val == node2.Val && check(node1.Left, node2.Right) && check(node1.Right, node2.Left)
}

// @lc code=end