【LeetCode】Sum Root to Leaf Numbers
题目
Given a binary tree containing digits from 0-9
only, each root-to-leaf path could represent
a number.
An example is the root-to-leaf path 1->2->3
which represents the number 123
.
Find the total sum of all root-to-leaf numbers.
For example,
1
/ \
2 3
The root-to-leaf path 1->2
represents the number 12
.
The root-to-leaf path 1->3
represents the number 13
.
Return the sum = 12 + 13 = 25
.
解答
用树的递归解决
/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int sumNumbers(TreeNode root) {
if(root==null){
return 0;
}
return sum(root,0);
} public int sum(TreeNode node,int parentVal){
int sum=0;
int temp=parentVal*10+node.val;
if(node.left==null&&node.right==null){
sum=temp;
}
if(node.left!=null){
sum+=sum(node.left,temp);
}
if(node.right!=null){
sum+=sum(node.right,temp);
}
return sum;
}
}
---EOF---
【LeetCode】Sum Root to Leaf Numbers的更多相关文章
- 【leetcode】Sum Root to Leaf Numbers(hard)
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- 【Leetcode】【Medium】Sum Root to Leaf Numbers (未完成)
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- 【树】Sum Root to Leaf Numbers
题目: Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a nu ...
- 【leetcode刷题笔记】Sum Root to Leaf Numbers
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- [LeetCode] 129. Sum Root to Leaf Numbers 求根到叶节点数字之和
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- leetcode@ [129] Sum Root to Leaf Numbers (DFS)
https://leetcode.com/problems/sum-root-to-leaf-numbers/ Given a binary tree containing digits from 0 ...
- leetcode 129. Sum Root to Leaf Numbers ----- java
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- [LeetCode] 129. Sum Root to Leaf Numbers 解题思路
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
- Java for LeetCode 129 Sum Root to Leaf Numbers
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number ...
随机推荐
- jquery结合Highcharts插件实现动态数据仪表盘图形化显示效果
仪表盘显示效果如图: 方法一效果图: 方法二效果图(插件版本4.0.1): js代码如下: $(function(){ //方法一: var chart = new Highcharts.Char ...
- java泛型问题 关于警告:XX is a raw type
(本文例子适用于JDK 5.0, 学习请先安装并配置!!!) 我们从一个简单的例子开始:假设我们现在需要一个专用来存储字符串的List,该如何实现?呵呵,这还不简单,且看如下代码: ...
- Delphi 实现Ini文件参数与TEdit和TCheckBox绑定(TSimpleParam)
在实际工作中,常遇到对Ini参数的修改,显示与保存问题. 如果手工写代码,会有很大的工作量. 本例把ini文件的参数与控件绑定起来,以达到方便使用的目的. 本例程共有2个单元 uSimpleParam ...
- java.util.Timer分析源码了解原理
Timer中最主要由三个部分组成: 任务 TimerTask . 任务队列: TaskQueue queue 和 任务调试者:TimerThread thread 他们之间的关系可以通过下面图示: ...
- Java HashSet和LinkedHashSet的用法
Java HashSet和LinkedHashSet的用法 类HashSet和LinkedHashSet都是接口Set的实现,两者都不能保存重复的数据.主要区别是HashSet不保证集合中元素的顺序, ...
- python教程,文章list
http://www.2cto.com/kf/web/Python/ http://www.v2ex.com/go/python http://www.sharejs.com/codes/python ...
- CC++初学者编程教程(2) Microsoft Visual C++ 6.0开发环境搭建
上一篇演示的是如何安装VS2010,本文演示的是如何安装Microsoft Visual C++ 6.0 简称VC6. 有同学经常VC6都是很古董的版本了,为啥他还存在,不得不说VC6是微软一个很经典 ...
- WISPr1.0
王桢珍 王兵 侯志强 苑红 中国移动研究院 网络技术研究所, 北京100053 摘要 本文详细介绍了WLAN国际漫游的WISPr1.0技术规范并探讨其具体实现,包括基于WISPr1.0的WLAN国 ...
- ubuntu中如何关闭防火墙?
只需要输入 root@stgman-desktop:~# sudo ufw disable 防火墙在系统启动时自动禁用
- collection系列用法-deque双向队列
deque双向队列 Deque可以从两端添加和删除元素.常用的结构,是它的简化版本. Deque支持序列的常用操作,现在举一个简单例子,你会发现其实跟平成的list没啥区别: import colle ...