Candy

Source

• lintcode: 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
Given ratings = [1, 2], return 3.

Given ratings = [1, 1, 1], return 3.

Given ratings = [1, 2, 2], return 4. ([1,2,1]).

Java

public class Solution {
    /**
     * @param ratings Children's ratings
     * @return the minimum candies you must give
     */
    public int candy(int[] ratings) {
        int len = ratings.length;
        int candy[] = new int[len];
        Arrays.fill(candy, 1);

        for(int i=1; i<len; i++){
            if(ratings[i]>ratings[i-1]){
                candy[i]=candy[i-1]+1;
            }
        }

        for(int i=len-2; i>=0; i--){
            if(ratings[i]>ratings[i+1]){
                candy[i] = Math.max(candy[i], candy[i+1]+1);
            }
        }

        int result=0;
        for(int i=0; i<len; i++){
            result+=candy[i];
        }
        return result;
    }
}