LeetCode Sum Root to Leaf Numbers

標籤：style   blog   color   io   ar   for   div   sp   log   

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.

 

 

 1 /** 2  * Definition for binary tree 3  * public class TreeNode { 4  *     int val; 5  *     TreeNode left; 6  *     TreeNode right; 7  *     TreeNode(int x) { val = x; } 8  * } 9  */10 public class Solution {    11     int sumnum=0;12     public int sumNumbers(TreeNode root) {          13         if (root==null) {14             return 0;15         }    16                 if ((root.left==null)&&(root.right==null)) {17             sumnum=sumnum+root.val;18             return sumnum;19         }20         21         sumNum(root.left, root.val);22         sumNum(root.right, root.val);23         return sumnum;24     }25     26     private    int sumNum(TreeNode root,int numroot){27         if (root==null) {28             return 0;29         }    30         if ((root.left==null)&&(root.right==null)) {31             sumnum=sumnum+numroot*10+root.val;32             return sumnum;33         }34             35             sumNum(root.left, numroot*10+root.val);36             sumNum(root.right, numroot*10+root.val);37             return 0;38         39     }40     }

 

LeetCode Sum Root to Leaf Numbers