[LeetCode] Path Sum 파이썬

class Solution:
    # @param root, a tree node
    # @param sum, an integer
    # @return a boolean
    def hasPathSum(self, root, sum):
        if root is None:
            return False

        if root.left is None and root.right is None and root.val == sum:
            return True

        return self.hasPathSum(root.left, sum - root.val) or self.hasPathSum(root.right, sum - root.val)

 

sum - curr_value 하면서 left, right node를 계속 탐색하다가 leaf 에 도착했을때 curr_value == sum-curr_value 이면 True

 

출처: github.com/jiapengwen/LeetCode/blob/master/Python/path-sum.py