-
Notifications
You must be signed in to change notification settings - Fork 40
/
MergeTwoBinaryTrees.js
50 lines (47 loc) · 1.29 KB
/
MergeTwoBinaryTrees.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
// Source : https://leetcode.com/problems/merge-two-binary-trees
// Author : Dean Shi
// Date : 2017-06-14
/***************************************************************************************
*
* Given two binary trees and imagine that when you put one of them to cover the other,
* some nodes of the two trees are overlapped while the others are not.
*
* You need to merge them into a new binary tree. The merge rule is that if two nodes
* overlap, then sum node values up as the new value of the merged node. Otherwise, the
* NOT null node will be used as the node of new tree.
*
* Example 1:
*
* Input:
* Output:
* Merged tree:
* 3
* / \
* 4 5
* / \ \
* 5 4 7
*
* Note:
* The merging process must start from the root nodes of both trees.
*
***************************************************************************************/
/**
* Definition for a binary tree node.
* function TreeNode(val) {
* this.val = val;
* this.left = this.right = null;
* }
*/
/**
* @param {TreeNode} t1
* @param {TreeNode} t2
* @return {TreeNode}
*/
var mergeTrees = function(t1, t2) {
if (!t1) return t2
if (!t2) return t1
t1.val += t2.val
t1.left = mergeTrees(t1.left, t2.left)
t1.right = mergeTrees(t1.right, t2.right)
return t1
};