Leetcode: Candy @Python

class Solution:
    # @param ratings, a list of integer
    # @return an integer
    def candy(self, ratings):
        n=len(ratings)
        candynum=[1]*n
        for i in range(1,n):
            if ratings[i]>ratings[i-1]:
                candynum[i]=candynum[i-1]+1
        for i in reversed(range(n-1)):
            if ratings[i]>ratings[i+1] and candynum[i]<=candynum[i+1]:
                candynum[i]=candynum[i+1]+1
        return sum(candynum)