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?
Input: [1,0,2] Output: 5 Explanation: You can allocate to the first, second and third child with 2, 1, 2 candies respectively.
Input: [1,2,2] Output: 4 Explanation: You can allocate to the first, second and third child with 1, 2, 1 candies respectively. The third child gets 1 candy because it satisfies the above two conditions.
class Solution: def candy(self, ratings: List[int]) -> int: res = *len(ratings) lbase = rbase = 1 # left scan for i in range(1, len(ratings)): lbase = lbase + 1 if ratings[i] > ratings[i-1] else 1 res[i] = lbase # right scan for i in range(len(ratings)-2, -1, -1): rbase = rbase + 1 if ratings[i] > ratings[i+1] else 1 res[i] = max(rbase, res[i]) return sum(res)