988. Smallest String Starting From Leaf

https://leetcode.com/problems/smallest-string-starting-from-leaf/

Smallest String Starting From Leaf - LeetCode

 

 

 

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
import heapq
class Solution(object):
    def smallestFromLeaf(self, root):
        """
        :type root: TreeNode
        :rtype: str
        """

        alphabet_list = list(string.ascii_lowercase)
        
        h = []
        def check_list(path):
            stringman = ""

            for i in range(len(path)-1, -1, -1):
                #print(i,"i")
                stringman += alphabet_list[path[i]]

            
            heapq.heappush(h, (stringman, stringman))

        
        def printview(root, path):
            
            if root:
                
                if not root.left and not root.right:
                    #print(root.val, path + [root.val], depth)
                    check_list(path+[root.val])
                printview(root.left, path +[root.val])
                printview(root.right, path + [root.val])
        
        path_list = []
        depth = 0
        printview(root, path_list)
        
        print(h)
        return heapq.heappop(h)[1]