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 a binary tree node. * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    //从根节点到叶子节点的路径代表一个数值，找出所有的这些数值然后累加得到一个和。DFS    //本题主要注意getRes函数的参数，path代表到达node节点时，路径上已经存在的和！    //本题注意题意：只有到达叶子节点（left=right=null）才能够将结果保存到res，所以注意递归结束条件    int res;    public int sumNumbers(TreeNode root) {        getRes(root,0);        return res;            }    public void getRes(TreeNode node,int path){
   //注意path参数含义！        if(node==null) return;        int temp=path*10+node.val;        if(node.left==null&&node.right==null){            res+=temp;            return;        }        getRes(node.left,temp);        getRes(node.right,temp);            }}