Function isSymmetric

symmetric_tree_101/solution.go:18–20

** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ Note: good problem! Review this. Use of two pointers to left and right subtree was a new idea to me. This allows us to check each side of the tree, which is differe

(root *TreeNode)

// This allows us to check each side of the tree, which is different to
// other recursive (pre, in, post) traversals that I'm familiar with.
func isSymmetric(root *TreeNode) bool {
	return isSym(root, root)
}

func isSym(left, right *TreeNode) bool {
	if left == nil && right == nil {