Sum Root to Leaf Numbers--leetcode

Given a binary tree containing digits from only 0-9 , 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 = + = 25 .

Title: To a binary tree, each node is a number between 0-9, from the root node to the leaf node represents a number, all of these numbers and.

Problem-solving ideas: This problem should be a study of DFS, can be directly DFS solution, or in the queue can also be used to do, the recent problem is no state, head a group of paste.

     Public intsumnumbers (TreeNode root) {returnSUM (root,0); }         Public intSUM (TreeNode node,intsum) {        if(node==NULL){            return0; }        if(node.left==NULL&&node.right==NULL) {sum=sum*10+Node.val; returnsum; }           returnSUM (node.left,sum*10+node.val) +sum (node.right,sum*10+node.val); }

Sum Root to Leaf Numbers--leetcode