LeetCode 129. Sum Root to Leaf Numbers

最新推荐文章于 2024-02-28 12:48:11 发布

LchinaM

最新推荐文章于 2024-02-28 12:48:11 发布

阅读量349

点赞数

分类专栏： leetcode

本文链接：https://blog.youkuaiyun.com/LchinaM/article/details/58629628

版权

leetcode 专栏收录该内容

75 篇文章

订阅专栏

本文介绍了一种算法，用于计算二叉树中所有从根节点到叶子节点的路径所代表数字的总和。通过递归遍历的方式，将每个路径转换为相应的数值并累加求和。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

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.

answer:

class Solution {
public:
    int sumNumbers(TreeNode* root) {
        int sum = 0;
        return mySum(root,sum);
    }
    
     
    int mySum(struct TreeNode* node, int sum){
        if(node == NULL)
            return 0;
        sum = sum * 10 + node->val;
        if(!node->left && !node->right)
            return sum;
        return mySum(node->left,sum) + mySum(node->right,sum);
    }
};