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README.md
src
- 0236_Lowest_Common_Ancestor_of_a_Binary_Tree
  - lca.go
  - lca_test.go
- README.md

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`@@ -116,6 +116,7 @@ continually updating 😃.`
`116`	`116`	* [226. Invert Binary Tree](src/0226_invert_binary_tree/invert_binary_tree.go)   `binary tree`
`117`	`117`	* [211. Add and Search Word - Data structure design](src/0211_add_and_search_word/add_and_search_word.go)   `trie`
`118`	`118`	* [235. Lowest Common Ancestor of a Binary Search Tree](src/0235_lowest_common_ancestor_of_a_binary_search_tree/lcaoabst.go)   `binary tree`
	`119`	+* [236. Lowest Common Ancestor of a Binary Tree](src/0236_Lowest_Common_Ancestor_of_a_Binary_Tree/lca.go)   `binary tree`
`119`	`120`	* [257. Binary Tree Paths](src/0257_binary_tree_paths/binary_tree_paths.go)   `binary tree`
`120`	`121`	* [307. Range Sum Query - Mutable](src/0307_Range_Sum_Query_Mutable/range_sum_query_mut.go)   `segment tree`
`121`	`122`	* [404. Sum of Left Leaves](src/0404_sum_of_left_leaves/sum_of_left_leaves.go)   `binary tree`

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	`1`	`+/*`
	`2`	`+236. Lowest Common Ancestor of a Binary Tree`
	`3`	`+https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/`
	`4`	`+*/`
	`5`	`+// 2019年02月21日`
	`6`	`+`
	`7`	`+package lca`
	`8`	`+`
	`9`	`+// TreeNode Definition for TreeNode.`
	`10`	`+type TreeNode struct {`
	`11`	`+ Val int`
	`12`	`+ Left *TreeNode`
	`13`	`+ Right *TreeNode`
	`14`	`+}`
	`15`	`+`
	`16`	`+func lowestCommonAncestor(root, p, q TreeNode) TreeNode {`
	`17`	`+ if root == nil \|\| root == p \|\| root == q {`
	`18`	`+ return root`
	`19`	`+ }`
	`20`	`+ left := lowestCommonAncestor(root.Left, p, q)`
	`21`	`+ right := lowestCommonAncestor(root.Right, p, q)`
	`22`	`+`
	`23`	`+ if left != nil && right != nil {`
	`24`	`+ return root`
	`25`	`+ }`
	`26`	`+ if left != nil {`
	`27`	`+ return left`
	`28`	`+ }`
	`29`	`+ return right`
	`30`	`+}`

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`@@ -0,0 +1,39 @@`
	`1`	`+package lca`
	`2`	`+`
	`3`	`+import "testing"`
	`4`	`+`
	`5`	`+func TestLCA(t *testing.T) {`
	`6`	`+ type arg struct {`
	`7`	`+ root, p, q *TreeNode`
	`8`	`+ }`
	`9`	`+`
	`10`	`+ tree := createBinaryTree([]int{6, 2, 8, 0, 4, 7, 9, -1, 1, 3, 5})`
	`11`	`+`
	`12`	`+ testCases := []arg{`
	`13`	`+ {root: tree, p: tree.Left.Right.Left, q: tree.Left.Right.Right},`
	`14`	`+ {p: &TreeNode{Val: 2}, q: &TreeNode{Val: 8}},`
	`15`	`+ }`
	`16`	`+ expected := []*TreeNode{{Val: 4}, nil}`
	`17`	`+`
	`18`	`+ for index, data := range testCases {`
	`19`	`+ if res := lowestCommonAncestor(data.root, data.p, data.q); res != nil && res.Val != expected[index].Val {`
	`20`	`+ t.Errorf("expected %v, got %v", expected[index], res)`
	`21`	`+ } else if res == nil && res != expected[index] {`
	`22`	`+ t.Errorf("expected %v, got %v", expected[index], res)`
	`23`	`+ }`
	`24`	`+ }`
	`25`	`+}`
	`26`	`+`
	`27`	`+func createBinaryTree(nums []int) *TreeNode {`
	`28`	`+ return performCreate(nums, 0)`
	`29`	`+}`
	`30`	`+`
	`31`	`+func performCreate(nums []int, index int) *TreeNode {`
	`32`	`+ if index >= len(nums) {`
	`33`	`+ return nil`
	`34`	`+ }`
	`35`	`+ root := &TreeNode{Val: nums[index]}`
	`36`	`+ root.Left = performCreate(nums, 2*index+1)`
	`37`	`+ root.Right = performCreate(nums, 2*index+2)`
	`38`	`+ return root`
	`39`	`+}`

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`77`	`77`	\|0219\|[219. Contains Duplicate II](0219_contains_duplicate_2/contains_duplicate_2.go)\|Easy\|`map`\|
`78`	`78`	\|0226\|[Invert Binary Tree](./0226_invert_binary_tree/invert_binary_tree.go)\|Easy\|`recursion; ` `binary tree`\|
`79`	`79`	\|0235\|[235. Lowest Common Ancestor of a Binary Search Tree](0235_lowest_common_ancestor_of_a_binary_search_tree/lcaoabst.go)\|Easy\|`recursion; ` `binary tree`\|
	`80`	+\|0236\|[236. Lowest Common Ancestor of a Binary Tree](0236_Lowest_Common_Ancestor_of_a_Binary_Tree/lca.go)\|Medium\|`recursion; ` `binary tree`\|
`80`	`81`	\|0237\|[237. Delete Node in a Linked List](0237_delete_node_in_a_linked_list/dniall.go)\|Easy\|`linked list`\|
`81`	`82`	\|0257\|[257. Binary Tree Paths](0257_binary_tree_paths/binary_tree_paths.go)\|Easy\|`binary tree`\|
`82`	`83`	\|0258\|[258. Add Digits](0258_add_digits/add_digits.go)\|Easy\|`math`\|

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