标签:style java color strong os art
题目
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
.
用树的递归解决
/** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public int sumNumbers(TreeNode root) { if(root==null){ return 0; } return sum(root,0); } public int sum(TreeNode node,int parentVal){ int sum=0; int temp=parentVal*10+node.val; if(node.left==null&&node.right==null){ sum=temp; } if(node.left!=null){ sum+=sum(node.left,temp); } if(node.right!=null){ sum+=sum(node.right,temp); } return sum; } }
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【LeetCode】Sum Root to Leaf Numbers,布布扣,bubuko.com
【LeetCode】Sum Root to Leaf Numbers
标签:style java color strong os art
原文地址:http://www.cnblogs.com/mengfanrong/p/3841290.html