原题地址：https://oj.leetcode.com/problems/candy/
题意：
There are N children standing in a line. Each child is assigned a rating value.
You are giving candies to these children subjected to the following requirements:
- Each child must have at least one candy.
- Children with a higher rating get more candies than their neighbors.
What is the minimum candies you must give?
解题思路：求最少的蛋糕数。先从前到后扫描一遍数组，如果序列递增，就+1；然后从后到前扫描一遍数组，序列递增，+1。保证最低谷（ratings最小）永远是1就可以了。
代码：
class Solution: # @param ratings, a list of integer # @return an integer def candy(self, ratings): candynum = [1 for i in range(len(ratings))] for i in range(1, len(ratings)): if ratings[i] > ratings[i-1]: candynum[i] = candynum[i-1] + 1 for i in range(len(ratings)-2, -1, -1): if ratings[i+1] < ratings[i] and candynum[i+1] >= candynum[i]: candynum[i] = candynum[i+1] + 1 return sum(candynum)