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?

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

Solution:

public class Solution {
    public int candy(int[] ratings) {
        if (ratings.length == 0) {
            return 0;
        }    

        int[] res = new int[ratings.length];

        res[0] = 1;

        for (int i = 1; i < ratings.length; i++) {
            if (ratings[i] > ratings[i-1]) {
                res[i] = res[i-1] + 1;
            } else {
                res[i] = 1;
            }
        }

        int count = res[ratings.length-1];

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

            count += res[i]; 
        }

        return count;
    }
}