find-mode-in-binary-search-tree.py

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def findMode(self, root):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        def visit(v):
            if v != self.pre:
                self.pre = v
                self.cnt = 0
            self.cnt += 1
            if self.cnt > self.maxFreq:
                self.maxFreq = self.cnt
                self.modeCnt = 1
            elif self.cnt == self.maxFreq:
                if self.ans:
                    self.ans[self.modeCnt] = v
                self.modeCnt += 1

        def inorder(root):
            if root:
                inorder(root.left)
                visit(root.val)
                inorder(root.right)
                
        self.pre = None
        self.ans = None
        self.maxFreq = self.modeCnt = self.cnt = 0
        inorder(root)
        self.ans = [0] * self.modeCnt
        self.modeCnt = self.cnt = 0
        inorder(root)
        return self.ans