lowest-common-ancestor-of-a-binary-tree.go

package main

func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {

	if root == nil || root == p || root == q {
		return root
	}

	left := lowestCommonAncestor(root.Left, p, q)
	right := lowestCommonAncestor(root.Right, p, q)

	if (left == p && right == q) || (left == q && right == p) {
		return root
	}

	if left != nil {
		return left
	}

	return right
}