[LeetCode] Sum Root to Leaf Numbers dfs,深度搜索

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.

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　　这题是简单地深度搜索bfs，代码如下:

#include <iostream>

using namespace std;



/**

 * 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) {

        unsigned int cur_val=0,ret_val=0;

        help_f(root,cur_val,ret_val);

        return ret_val;

    }

    void help_f(TreeNode *node,unsigned int &cur_val,unsigned int &ret_val)

    {

        if(node==NULL)  return ;

        cur_val=cur_val*10+node->val;

        help_f(node->left,cur_val,ret_val);

        help_f(node->right,cur_val,ret_val);

        if(node->left==NULL&&node->right==NULL) ret_val+=cur_val;

        cur_val/=10;

    }

};



int main()

{



    return 0;

}

View Code