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

package main

func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
	if root == nil {
		return nil
	}
	if root == p || root == q {
		return root
	}
	left := lowestCommonAncestor(root.Left, p, q)
	right := lowestCommonAncestor(root.Right, p, q)
	if left != nil && right != nil {
		return root
	}
	if left == nil && right == nil {
		return nil
	}
	if left != nil {
		return left
	} else {
		return right
	}
}