和大神们学习每天一题(leetcode)-Sum Root to Leaf Numbers

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.

本题主要在于计算根节点到当前节点的积累值

功能测试用例：{ 1,0,4,#,#,#,3,5,#,#,#}

特殊输入测试用例：NULL, {1}

class Solution {public:int nSum;void SumProcess(TreeNode*root,int nNum)//nNum是从根节点到当前节点所有路径的值的和{if (root->left == NULL&&root->right == NULL)//如果为叶子节点则nNum为当前这一路径积累值nSum += nNum;if (root->left)//左子树不为空则向左遍历SumProcess(root->left,nNum * 10 + root->left->val);if (root->right)//右子树不为空则向右遍历SumProcess(root->right, nNum * 10 + root->right->val);}int sumNumbers(TreeNode *root) {if (root == NULL)return 0;if (root->left == NULL&&root->right == NULL)return root->val;nSum = 0;//根节点到所有叶子节点路径的和SumProcess(root, root->val);return nSum;}};