# Question

Formatted question description: https://leetcode.ca/all/236.html

 236. Lowest Common Ancestor of a Binary Tree

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

According to the definition of LCA on Wikipedia:
“The lowest common ancestor is defined between two nodes v and w
as the lowest node in T that has both v and w as descendants
(where we allow a node to be a descendant of itself).”

_______3______
/              \
___5__          ___1__
/      \        /      \
6      _2      0        8
/  \
7   4

For example, the lowest common ancestor (LCA) of nodes 5 and 1 is 3.
Another example is LCA of nodes 5 and 4 is 5, since a node can be a descendant of itself according to the LCA definition.

@tag-tree


# Algorithm

The very simple idea is to see where the two values are compared with root:

• Both values are on the left, then LCA is on the left
• Both values are on the right, then LCA is on the right
• One on the left and one on the right means that LCA is the current root node.

Java