[LeetCode][JavaScript]Path Sum II

Path Sum II

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.

For example:
Given the below binary tree and sum = 22,

              5
             / \
            4   8
           /   / \
          11  13  4
         /  \    / \
        7    2  5   1

return

[
   [5,4,11,2],
   [5,8,4,5]
]

https://leetcode.com/problems/path-sum-ii/

 

 

 

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求出所有等于sum的从根到叶子的路径。

还是跟上两题一样的思路。

Binary Tree Paths : http://www.cnblogs.com/Liok3187/p/4735368.html

Path Sum : http://www.cnblogs.com/Liok3187/p/4869521.html

 

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @param {number} sum
 * @return {number[][]}
 */
var pathSum = function(root, sum) {
    var res = [];
    if(root && root.val !== undefined){
        getPathSum(root, [], 0);
    }
    return res;

    function getPathSum(node, path, value){
        var isLeaf = true, tmp;
        if(node.left){
            isLeaf = false;
            getPathSum(node.left, path.concat(node.val), value + node.val);
        }
        if(node.right){
            isLeaf = false;
            getPathSum(node.right, path.concat(node.val), value + node.val);
        }
        if(isLeaf){
            tmp = value + node.val;
            if(tmp === sum){
                res.push(path.concat(node.val));
            }
        }
    }
};