Python每日一练(20230417) 最大间距、Z字形变换、买卖股票最佳时机II

class Solution(object):
    def maximumGap(self, nums):
        if len(nums) < 2:
            return 0
        min_val, max_val = min(nums), max(nums)
        if min_val == max_val:
            return 0
        n = len(nums) + 1
        step = (max_val - min_val) // n
        exist = [0 for _ in range(n + 1)]
        max_num = [0 for _ in range(n + 1)]
        min_num = [0 for _ in range(n + 1)]
        for num in nums:
            idx = self.findBucketIndex(num, min_val, max_val, n)
            max_num[idx] = num if not exist[idx] else max(num, max_num[idx])
            min_num[idx] = num if not exist[idx] else min(num, min_num[idx])
            exist[idx] = 1
        res = 0
        pre = max_num[0]
        for i in range(1, n + 1):
            if exist[i]:
                res = max(res, min_num[i] - pre)
                pre = max_num[i]
        return res
    def findBucketIndex(self, num, min_val, max_val, n):
        return int((num - min_val) * n / (max_val - min_val))
        return max(depth)
# %%
s = Solution()
nums = [3,6,9,1]
print(s.maximumGap(nums))

import math
class Solution:
    def convert(self, s: str, numRows: int) -> str:
        n = len(s)
        N = numRows
        if n == 1 or N == 1:
            return s
        S = N-2
        C = 2*N-2
        R = int(math.floor(n/C))
        RS = n % (C)
        CE = n-R*C
        RR = 1 if (RS <= N) else 1+(RS-N)
        RX = R*(N-1) + RR
        output = []
        i = 0
        while i < N:
            j = 0
            k = (N-1-i)
            while j < RX:
                r = int(math.floor(j/(N-1)))
                rs = j % (N-1)
                offset = i if rs == 0 else N+rs-1
                index = r*C+offset
                if index < len(s):
                    output.append(s[index])
                if i > 0 and i < N-1:
                    r = int(math.floor(k/(N-1)))
                    rs = k % (N-1)
                    offset = i if rs == 0 else N+rs-1
                    index = r*C+offset
                    if index < len(s):
                        output.append(s[index])
                j += (N-1)
                k += (N-1)
            i += 1
        return ''.join(output)
# %%
s = Solution()
print(s.convert('PAYPALISHIRING', 3))
print(s.convert('PAYPALISHIRING', 4))

class Solution(object):
    def maxProfit(self, prices):
        """
        :type prices: List[int]
        :rtype: int
        """
        hold = 0
        pric = []
        temp = []
        flag = 0
        msum = 0
        if len(prices) <= 2:
            if not prices:
                return 0
            if len(prices) == 1:
                return 0
            if prices[0] > prices[1]:
                return 0
            if prices[0] < prices[1]:
                return prices[1] - prices[0]
        for i in range(len(prices) - 1):
            if prices[i + 1] > prices[i] and hold != 1:
                hold = 1
                flag = i
                continue
            if prices[i + 1] < prices[i] and hold == 1:
                pric.append(prices[flag])
                pric.append(prices[i])
                hold = 0
            else:
                continue
        for i in range(0, len(pric), 2):
            temp.append(pric[i + 1] - pric[i])
            msum = sum(temp)
        if hold == 1:
            msum = msum + prices[-1] - prices[flag]
        return msum
# %%
s = Solution()
prices = [7,1,5,3,6,4]
print(s.maxProfit(prices))
prices = [1,2,3,4,5]
print(s.maxProfit(prices))
prices = [7,6,4,3,1]
print(s.maxProfit(prices))