135.分糖果

class Solution:
    def candy(self, ratings: List[int]) -> int:
        n = len(ratings);
        if n==0 : return 0
        #初始化数组,每个人最少有一个糖果
        nums = [1] * n
        #从左到右遍历一次进行比较
        for i in range(1,n):
            if ratings[i] > ratings[i-1]:
                nums[i] = nums[i-1] + 1
        #从右到左遍历一次进行比较
        for i in range(n-1,0,-1):
            if ratings[i] < ratings[i-1]:
                nums[i-1] = max(nums[i-1],nums[i]+1)
        #累计结果
        return sum(nums)