LeetCode--Sum Root to Leaf Numbers

标签：leetcode   traversal   深度优先搜索   递归   

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.

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution 
{
public:
    int sumNumbers(TreeNode *root) 
	{
        int now = 0;
        int sum = 0;
        sumMumbers(root,now,sum);
        return sum;
    }
	void sumMumbers(TreeNode* root, int now, int& sum)
	{
		if(root == NULL)
			return;
		if(root->left==NULL && root->right==NULL)
		{
			sum = sum + now*10+root->val;
			return ;
		}
		if(root->left != NULL)
			sumMumbers(root->left,now*10+root->val,sum);
		if(root->right != NULL)
			sumMumbers(root->right,now*10+root->val,sum);
		return ;
	}
};

LeetCode--Sum Root to Leaf Numbers

标签：leetcode   traversal   深度优先搜索   递归   

原文地址：http://blog.csdn.net/shaya118/article/details/42721909