Python每日一练(20230403) 随机正整数、微博热门话题、恢复二叉搜索树

def fun():
    random_list = [random.randint(10, 99) for n in range(100)]
    statistics = {n: 0 for n in range(10)}
    for index, x in enumerate(random_list):
        print(x, end=' ')
        statistics[int(x % 10)] = statistics[int(x % 10)] + 1
        if ((index + 1) % 10 == 0):
            print()
    print(statistics)
if __name__ == '__main__':
    fun()

import re
a = int(input('输入微博数量（小于等于105的正整数）：'))
b = []
c = []
while len(b)<a:
    x = input('请输入微博内容，小于140字：')
    if len(x)<140:
        b.append(x)
    else:
        print('信息超出140字限制，请从新输入。')
    c += re.findall('#[^#]+#',x)
d = [{'n':n,'c':len(c)-len(re.findall('#[^#]+#',re.sub(n,'',''.join(c.copy()))))} for n in set(c)]
e = sorted(d,key=lambda x:x['c'],reverse=True)
print(e[0]['n'].title())
print(e[0]['c'])

import sys
class TreeNode(object):
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None
    def to_list(self, count):
        queue = []
        queue.append(self)
        result = []
        while len(queue) > 0:
            if count == 0:
                break
            node = queue.pop(0)
            if node is None:
                result.append(None) #直接用None代替'null'
            else:
                count -= 1
                result.append(node.val)
                queue.append(node.left)
                queue.append(node.right)
        #增加去掉尾部None的处理
        while result[-1] is None:
            result.pop()
        return result
class List2Tree(object):
    def __init__(self, nums: list):
        self.nums = nums
        self.queue = []
        if len(nums) == 1:
            self.root = TreeNode(self.nums.pop(0))
        else:
            a = self.nums.pop(0)
            b = self.nums.pop(0)
            c = self.nums.pop(0)
            self.root = TreeNode(a)
            if b is not None:
                self.root.left = TreeNode(b)
            else:
                self.root.left = b
            if c is not None:
                self.root.right = TreeNode(c)
            else:
                self.root.right = c
            self.queue.append(self.root.left)
            self.queue.append(self.root.right)
    def convert(self):
        while len(self.nums) > 0 and len(self.queue) > 0:
            node = self.queue.pop(0)
            if node is not None:
                num = self.nums.pop(0)
                if num is not None:
                    node.left = TreeNode(num)
                else:
                    node.left = num
                if len(self.nums) > 0:
                    num = self.nums.pop(0)
                else:
                    num = None
                if num is not None:
                    node.right = TreeNode(num)
                else:
                    node.right = num
                self.queue.append(node.left)
                self.queue.append(node.right)
        return self.root
class Solution(object):
    def __init__(self):
        self.first = self.second = None
        self.pre = TreeNode(-sys.maxsize - 1)
    def recoverTree(self, root):
        length = len(root)
        root = List2Tree(root).convert()
        self.traverse(root)
        self.first.val, self.second.val = self.second.val, self.first.val
        return root.to_list(length)
    def traverse(self, root):
        if root is None:
            return
        self.traverse(root.left)
        if self.pre.val >= root.val:
            if self.first is None:
                self.first = self.pre
            if self.first is not None:
                self.second = root
        self.pre = root
        self.traverse(root.right)
# %%
s = Solution()
print(s.recoverTree(root=[1, 3, None, None, 2]))
s = Solution()
print(s.recoverTree(root=[3, 1, 4, None, None, 2]))