[二叉树]617.|[二叉树]617. Merge Two Binary Trees
题目:617. Merge Two Binary Trees
一般的二叉树合并。若两个node重叠,则value等于它们的和。
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:
Tree 1Tree 2
12
/ \/ \
3213
/\\
547
Output:
Merged tree:
3
/ \
45
/ \\
547
Note: The merging process must start from the root nodes of both trees.
【[二叉树]617.|[二叉树]617. Merge Two Binary Trees】思路:同时遍历两棵树。
左树为空就返回右树,反之返回左树,两树不空就返回和。
class Solution {
public TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
if(t1 == null){return t2;
}
if(t2 == null){return t1;
}TreeNode t3 = new TreeNode(0);
t3.val = t1.val + t2.val;
t3.left = mergeTrees(t1.left, t2.left);
t3.right = mergeTrees(t1.right, t2.right);
return t3;
}
}
推荐阅读
- 斑驳的树影
- 求解 RMQ 的几种方式 :「递归分治」&「线段树」&「单调栈」
- 特辑(线段树)
- 猎人(八)
- 做一棵树
- 数据结构|数据结构 2 字符串 数组、二叉树以及二叉树的遍历
- leetcode|leetcode 105. 从前序与中序遍历序列构造二叉树 javascript
- 机器学习|(8)机器学习——SVM、决策树、朴素贝叶斯、KNN、K-means、随机森林、Adaboost
- 机器学习|机器学习(八)KNN,SVM,朴素贝叶斯,决策树与随机森林
- 数据结构|红黑树(RBTree)原理及实现