LeetCode 之 Sum Root to Leaf Numbers
来源:互联网 发布:淘宝售后客服怎么应聘 编辑:程序博客网 时间:2024/04/30 21:00
原题:
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.
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
.
解题思路:
在每个节点将父节点传下来的的值乘以10加上自己的val,可以获得一个值,然后把这个值传到左右子节点上,最后如果处理到叶子节点的时候,可以得到一条路径的值,然后把所有的路径的和都加在一个int里就可以,要加在一个int,就需要在传参的时候传地址。如图:
代码如下( 20 ms):
class Solution {public: int sumNumbers(TreeNode *root) { // IMPORTANT: Please reset any member data you declared, as // the same Solution instance will be reused for each test case. if(root==NULL) return 0; int result = 0; DFS(root , 0 , result); return result; } void DFS(TreeNode *root , int num , int &result ){ //由于需要保存层的信息,声明一个vector保存两个int //第一个为level信息,叶子为1层,别的都保存10^层数,第二层保存10,第三层保存100 int level = num*10+root->val; if(root->left==NULL && root->right==NULL){ //叶子节点 result+=level; return; } if(root->left){ DFS(root->left , level , result); } if(root->right){ DFS(root->right , level , result); } }};
- LeetCode之sum root to leaf numbers
- leetcode之Sum Root to Leaf Numbers
- LeetCode 之 Sum Root to Leaf Numbers
- LeetCode之Sum Root to Leaf Numbers
- LeetCode之Sum Root to Leaf Numbers
- LeetCode之Sum Root to Leaf Numbers
- leetcode之Sum Root to Leaf Numbers
- leetcode之 Sum Root to Leaf Numbers
- LeetCode 之 Sum Root to Leaf Numbers
- 做leetcode之Sum Root to Leaf Numbers的感悟
- leetcode 86: Sum Root to Leaf Numbers
- [LeetCode] Sum root to leaf numbers
- LeetCode : Sum Root to Leaf Numbers
- [leetcode] Sum Root to Leaf Numbers
- 【leetcode】Sum Root to Leaf Numbers
- leetcode:Sum Root to Leaf Numbers
- [LeetCode]Sum Root to Leaf Numbers
- [Leetcode]Sum Root to Leaf Numbers
- paip.2013年技术趋势以及热点 v2.0 cae
- Android Telephony系统 之 DataConnectionTracker与MobileDataStateTracker之间的通信
- 筛选法及预处理
- Percona Toolkit for MySQL安装(CentOS5.8)
- NGUI ,鼠标检测UI 用到的方法
- LeetCode 之 Sum Root to Leaf Numbers
- extJs form表单textfield中包含中文的长度验证问题
- HashMap原理机制自问自答
- 今天,我,离职了
- C专家编程
- 关于centos ssh无密登录失败的记录
- 文件乱问题
- 黑马程序员:正则表达式介绍:QQ匹配、E-mail提取应用
- 使用Web.config