leetcode-algorithms/python/path_sum.py at master · anishLearnsToCode/leetcode-algorithms · GitHub

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# Definition for a binary tree node.

class TreeNode:

def __init__(self, val=0, left=None, right=None):

self.val = val

self.left = left

self.right = right

class Solution:

def _is_leaf_node(self, node: TreeNode) -> bool:

return node.left is None and node.right is None

def _has_path_sum(self, root: TreeNode, target: int, currentSum: int) -> bool:

if root is None:

return False

currentSum += root.val

if self._is_leaf_node(root):

return currentSum == target

return self._has_path_sum(root.left, target, currentSum) or \

self._has_path_sum(root.right, target, currentSum)

def hasPathSum(self, root: TreeNode, targetSum: int) -> bool:

if root is None:

return False

return self._has_path_sum(root, targetSum, 0)

root = TreeNode(val=1)

root.right = TreeNode(val=2)

print(Solution().hasPathSum(root, 3))

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