113. 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.

Note: A leaf is a node with no children.

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]
]

解题分析

利用回溯+深度优先搜索即可解决。

这样要重点注意的是：回溯时，前进和后退要成对出现。

link:{sourcedir}/_0113_PathSumII.java[role=include]