代码随想录Day23 | LeetCode 455. 分发饼干、LeetCode 53. 最大子数组和、LeetCode 376. 摆动序列

LeetCode 455. 分发饼干

贪心就是干

class Solution:
    def findContentChildren(self, g: List[int], s: List[int]) -> int:
        g.sort(reverse = True)
        s.sort(reverse = True)
        i = j = 0
        res = 0
        while i < len(g) and j < len(s):
            if g[i] <= s[j]:
                res += 1
                j += 1
            i+= 1
        return res

LeetCode 53. 最大子数组和

贪心就是干

class Solution:
    def maxSubArray(self, nums: List[int]) -> int:
        res = float('-inf')
        sum_ = 0
        for num in nums:
            sum_ += num
            res = max(sum_, res)
            if sum_ < 0:
                sum_ = 0
        return res

贪心就是干

LeetCode 376. 摆动序列

class Solution:
    def wiggleMaxLength(self, nums: List[int]) -> int:
        if len(nums) < 2:
            return len(nums)
        preDiff = 0
        # curDiff = 0
        res = 1
        for i in range(len(nums) - 1):
            curDiff = nums[i + 1] - nums[i]
            if curDiff != 0 and curDiff * preDiff <= 0:
                res += 1
                preDiff = curDiff
        return res