text: '''
  URL: https://leetcode.com/problems/path-sum/
  
  Difficulty: Easy
  
  Description: Path Sum
  
  Given the root of a binary tree and an integer targetSum, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals targetSum.
  
  A leaf is a node with no children.
  
   
  
  Example 1:
  
  
  Input: root = [5,4,8,11,null,13,4,7,2,null,null,null,1], targetSum = 22
  Output: true
  Example 2:
  
  
  Input: root = [1,2,3], targetSum = 5
  Output: false
  Example 3:
  
  Input: root = [1,2], targetSum = 0
  Output: false
   
  
  Constraints:
  
  The number of nodes in the tree is in the range [0, 5000].
  -1000 <= Node.val <= 1000
  -1000 <= targetSum <= 1000
  
  '''
  
  # 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 hasPathSum(self, root, sum, currSum=0):
  
          if root:
  
              # leaf
              if root.left == None and root.right == None:
                  return currSum + root.val == sum
  
              else:
                  return self.hasPathSum(root.left, sum, currSum + root.val) or self.hasPathSum(root.right, sum, currSum + root.val)
  
          else:
              return False
  