<reponame>allandproust/leetcode-share<filename>python/113 Path Sum II.py<gh_stars>100-1000
'''
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]
]
'''

# Definition for a binary tree node.
class TreeNode(object):
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None


class Solution(object):
    def pathSum(self, root, sum):
        """
        :type root: TreeNode
        :type sum: int
        :rtype: List[List[int]]
        """
        result = []
        self._pathSum(root, sum, [], result)
        return result

    def _pathSum(self, root, sum, curr, result):
        if not root:
            return
        sum -= root.val
        if sum == 0 and root.left is None and root.right is None:
            result.append(curr + [root.val])
        if root.left:
            self._pathSum(root.left, sum, curr + [root.val], result)
        if root.right:
            self._pathSum(root.right, sum, curr + [root.val], result)


if __name__ == "__main__":
    None