[LeetCode]129. Sum Root to Leaf Numbers
来源:互联网 发布:反网络控制软件 编辑:程序博客网 时间:2024/06/05 15:27
https://leetcode.com/problems/sum-root-to-leaf-numbers/
根节点到叶子节点组成一个数字,找出所有数字的和
树的问题:递归+递归函数内有一个参数记录某种状态。记录状态两种:bottom To top && top To bottom,一条路走不通就走另一条!!!
传一个参数sum,表示根节点到当前位置的数字和。最开始想错,一直考虑从叶子节点到根节点,因为叶子节点到当前节点的表示数字位数各不相同,很难记录。
public class Solution { public int sumNumbers(TreeNode root) { return sumNumbers(root, 0); } private int sumNumbers(TreeNode root, int sum) { if (root == null) { return 0; } else if (root.left == null && root.right == null) { return sum * 10 + root.val; } else { return sumNumbers(root.left, sum * 10 + root.val) + sumNumbers(root.right, sum * 10 + root.val); } }}
0 0
- [LeetCode]129.Sum Root to Leaf Numbers
- LeetCode 129. Sum Root to Leaf Numbers
- [leetcode] 129.Sum Root to Leaf Numbers
- 【leetcode】129. Sum Root to Leaf Numbers
- [leetcode] 129. Sum Root to Leaf Numbers
- [LeetCode]129. Sum Root to Leaf Numbers
- 129. Sum Root to Leaf Numbers LeetCode
- [LeetCode]129. Sum Root to Leaf Numbers
- leetcode 129. Sum Root to Leaf Numbers
- Leetcode 129. Sum Root to Leaf Numbers
- LeetCode *** 129. Sum Root to Leaf Numbers
- LeetCode-129.Sum Root to Leaf Numbers
- LeetCode 129. sum-root-to-leaf-numbers
- LeetCode - 129. Sum Root to Leaf Numbers
- LeetCode 129. Sum Root to Leaf Numbers
- [leetcode] 129. Sum Root to Leaf Numbers
- [LeetCode] 129. Sum Root to Leaf Numbers
- Leetcode-129. Sum Root to Leaf Numbers
- JAVA多线程 浅入Concurrent包
- 分割窗口QSplitter
- Airbnb的开源项目Lottie简易实现动画
- OpenStack:glance_store:_drivers/filesystem.py文件源码学习-01
- Sublime Text3注册码(可用)
- [LeetCode]129. Sum Root to Leaf Numbers
- Wpf浏览器开发 开始篇1
- html meta标签作用
- pl330 dmac驱动分析2----关键函数
- 三、 平衡查找树之红黑树
- css3 2d转换3d转换以及动画的知识点汇总
- 1044. Shopping in Mars (25)-二分(难)
- 首页视频内循环
- nova 组件-pause/suspend