100. Same Tree
Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
Example 1:
Input: 1 1
/ \ / \
2 3 2 3
[1,2,3], [1,2,3]
Output: true
Example 2:
Input: 1 1
/ \
2 2
[1,2], [1,null,2]
Output: false
Example 3:
Input: 1 1
/ \ / \
2 1 1 2
[1,2,1], [1,1,2]
Output: false
Code:
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
que1,que2=collections.deque([p]),collections.deque([q])
if not p and not q:
return True
if (not p and q) or (p and not q):
return False
while que1 and que2:
node1,node2=que1.popleft(),que2.popleft()
if node1 and not node2:
return False
if node2 and not node1:
return False
if not node1 and not node2:
continue
if node1 and node2:
if node1.val != node2.val:
return False
que1.append(node1.left)
que1.append(node1.right)
que2.append(node2.left)
que2.append(node2.right)
return True
d = collections.deque([])
d.append('a') # 在最右边添加一个元素,此时 d=deque('a')
d.appendleft('b') # 在最左边添加一个元素,此时 d=deque(['b', 'a'])
d.extend(['c','d']) # 在最右边添加所有元素,此时 d=deque(['b', 'a', 'c', 'd'])
d.extendleft(['e','f']) # 在最左边添加所有元素,此时 d=deque(['f', 'e', 'b', 'a', 'c', 'd'])
d.pop() # 将最右边的元素取出,返回 'd',此时 d=deque(['f', 'e', 'b', 'a', 'c'])
d.popleft() # 将最左边的元素取出,返回 'f',此时 d=deque(['e', 'b', 'a', 'c'])
d.rotate(-2) # 向左旋转两个位置(正数则向右旋转),此时 d=deque(['a', 'c', 'e', 'b'])
d.count('a') # 队列中'a'的个数,返回 1
d.remove('c') # 从队列中将'c'删除,此时 d=deque(['a', 'e', 'b'])
d.reverse() # 将队列倒序,此时 d=deque(['b', 'e', 'a'])