There are n
children standing in a line. Each child is assigned a rating value given in the integer array ratings
.
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.
Return the minimum number of candies you need to have to distribute the candies to the children.
Example 1:
Input: ratings = [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: ratings = [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.
Constraints:
n == ratings.length
1 <= n <= 2 * 10^4
0 <= ratings[i] <= 2 * 10^4
老师想给孩子们分发糖果,有 N 个孩子站成了一条直线,老师会根据每个孩子的表现,预先给他们评分。你需要按照以下要求,帮助老师给这些孩子分发糖果:
- 每个孩子至少分配到 1 个糖果。
- 评分更高的孩子必须比他两侧的邻位孩子获得更多的糖果。
那么这样下来,老师至少需要准备多少颗糖果呢?
- 本题的突破口在于,评分更高的孩子必须比他两侧的邻位孩子获得更多的糖果,这句话。这个规则可以理解为 2 条规则,想象成按身高排队,站在下标为 0 的地方往后“看”,评分高即为个子高的,应该比前面个子矮(评分低)的分到糖果多;站在下标为 n - 1 的地方往后“看”,评分高即为个子高的,同样应该比前面个子矮(评分低)的分到糖果多。你可能会有疑问,规则都是一样的,为什么会出现至少需要多少糖果呢?因为可能出现评分一样高的同学。扫描数组两次,处理出每一个学生分别满足左规则或右规则时,最少需要被分得的糖果数量。每个人最终分得的糖果数量即为这两个数量的最大值。两次遍历结束,将所有糖果累加起来即为至少需要准备的糖果数。由于每个人至少分配到 1 个糖果,所以每个人糖果数再加一。
package leetcode funccandy(ratings []int) int { candies:=make([]int, len(ratings)) fori:=1; i<len(ratings); i++ { ifratings[i] >ratings[i-1] { candies[i] +=candies[i-1] +1 } } fori:=len(ratings) -2; i>=0; i-- { ifratings[i] >ratings[i+1] &&candies[i] <=candies[i+1] { candies[i] =candies[i+1] +1 } } total:=0for_, candy:=rangecandies { total+=candy+1 } returntotal }