python-leetcode题解之第993题二叉树的堂兄弟节点.zip

''' In a binary tree, the root node is at depth 0, and children of each depth k node are at depth k+1. Two nodes of a binary tree are cousins if they have the same depth, but have different parents. We are given the root of a binary tree with unique values, and the values x and y of two different nodes in the tree. Return true if and only if the nodes corresponding to the values x and y are cousins. Input: root = [1,2,3,4], x = 4, y = 3 Output: false ''' # 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 adjacent(self, root, node1, node2): if not root: return False value = False if (root.right and root.left): value = ((root.left.val == node1 and root.right.val == node2) or (root.left.val == node2 and root.right.val == node1)) return (value or self.adjacent(root.left, node1, node2) or self.adjacent(root.right, node1, node2)) def _level(self, root, node, level): if not root: return 0 if root.val == node: return level left_level = self._level(root.left, node, level+1) if left_level != 0: return left_level return self._level(root.right, node, level+1) def isCousins(self, root, x, y): """ :type root: TreeNode :type x: int :type y: int :rtype: bool """ if ((self._level(root, x, 1) == self._level(root, y, 1)) and not self.adjacent(root, x, y)): return True return False