[Leetcode] (python): 113 Path Sum II

Source of the topic

https://leetcode.com/problems/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.

Test instructions Analysis

input:a binary tree, sum

Output:list of the list.

Conditions: Given a binary tree, returns the path value of all root-leaf and the path equal to sum.

Topic ideas

Passed through a valuelist. DFS recursion

AC Code (PYTHON)

1 #Definition for a binary tree node.2 #class TreeNode (object):3 #def __init__ (self, x):4 #self.val = x5 #self.left = None6 #self.right = None7 8 classsolution (object):9     defpathsum (self, Root, sum):Ten         """ One : Type Root:treenode A : Type Sum:int - : Rtype:list[list[int]] -         """ the         defdfs (Root, Currsum, valuelist): -             ifRoot.left = = None andRoot.right = =None: -                 ifCurrsum = =sum:res.append (valuelist) -             ifRoot.left: +DFS (Root.left, Currsum+root.left.val, valuelist+[Root.left.val]) -             ifRoot.right: +DFS (Root.right, currsum+root.right.val,valuelist+[Root.right.val]) A          atres = [] -         ifRoot ==none:returnRes - dfs (Root, Root.val, [Root.val]) -         returnRes

[Leetcode] (python): 113 Path Sum II