Description
https://leetcode.com/problems/candy/
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?
Example 1:
Input: [1,0,2] Output: 5 Explanation: You can allocate to the first, second and third child with 2, 1, 2 candies respectively.
Example 2:
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.
Explanation
Python Solution
class Solution:
def candy(self, ratings: List[int]) -> int:
candies = [1 for i in range(len(ratings))]
for i in range(1, len(ratings)):
if ratings[i] > ratings[i - 1]:
candies[i] = candies[i - 1] + 1
for i in range(len(ratings) - 2, -1, -1):
if ratings[i + 1] < ratings[i] and candies[i + 1] >= candies[i]:
candies[i] = candies[i + 1] + 1
return sum(candies)
- Time Complexity: ~N
- Space Complexity: ~N