135. Candy
greedy的问题一般就是从左到右或者从右到左，或者正向排序反向排序。
class Solution(object):
def candy(self, ratings):
"""
:type ratings: List[int]
:rtype: int
"""
# greedy的方法，
# 从左到右递增的多拿一块
# 从右到左的时候要比较一下当前值
c = [1 for _ in range(len(ratings))]
for i in range(1, len(ratings)):
if ratings[i] > ratings[i-1]:
c[i] = c[i-1] + 1
for i in range(len(ratings)-1)[::-1]:
if ratings[i] > ratings[i+1]:
c[i] = max(c[i], c[i+1] + 1)
return sum(c)
