leetcode#112 Path Sum

1. 문제

• https://leetcode.com/problems/path-sum/
  

2. 나의 풀이

class Solution(object):
    def hasChild(self, node):
        if node and node.left:
            return True
        if node and node.right:
            return True
        return False
    
    def isTargetSumExist(self, node, prevSum, target):
        # Is not node => Not found path => False
        if not node:
            return False
        
        newSum = prevSum + node.val
        
        if not self.hasChild(node):
            if newSum == target:
                return True
            else:
                return False
           
        if(self.isTargetSumExist(node.left, newSum, target)):
            return True
        
        if(self.isTargetSumExist(node.right, newSum, target)):
            return True
        return False
        
    def hasPathSum(self, root, targetSum):
        """
        :type root: TreeNode
        :type targetSum: int
        :rtype: bool
        """
        
        return self.isTargetSumExist(root, 0, targetSum)

3. 남의 풀이