Candy.java

/*
    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?

    Link: https://leetcode.com/problems/candy/

    Example: None

    Solution: In this task, we use arrays fill to fill new list with all number 1.
    
    Source: None
*/

public class Solution {
    public int candy(int[] ratings) {
        if (ratings == null || ratings.length == 0) {
            return 0;
        }
        int[] count = new int[ratings.length];
        Arrays.fill(count, 1);
        int sum = 0;
        for (int i = 1; i < ratings.length; i++) {
            if (ratings[i] > ratings[i - 1]) {
                count[i] = count[i - 1] + 1;
            }
        }
        for (int i = ratings.length - 1; i >= 1; i--) {
            sum += count[i];
            if (ratings[i - 1] > ratings[i] && count[i - 1] <= count[i]) {
                count[i - 1] = count[i] + 1;
            }
        }
        sum += count[0];
        return sum;
    }
}