Distribute Candy Problem

Distribute Candy Problem

There are N children standing in a line with some rating value. You want to distribute a minimum number of candies to these children such that:

Each child must have at least one candy.
The children with higher ratings will have more candies than their neighbors.
You need to write a program to calculate the minimum candies you must give.

class Program
    {
        public static void Main(string[] args)
        {
            var ratings = new int[] { 1, 5, 2, 1 };

            var leftArray = Enumerable.Repeat(1, ratings.Length).ToArray();
            var rightArray = Enumerable.Repeat(1, ratings.Length).ToArray();

            var left = 1;

            while (left < ratings.Length)
            {
                if (ratings[left] > ratings[left - 1])
                    leftArray[left] = leftArray[left - 1] + 1;

                left++;
            }

            var right = ratings.Length - 2;

            while (right >= 0)
            {
                if (ratings[right] > ratings[right + 1])
                    rightArray[right] = rightArray[right + 1] + 1;

                right--;
            }

            var max = 0;
            for (int i = 0; i < ratings.Length; i++)
            {
                max = max + Math.Max(leftArray[i], rightArray[i]);
            }
            Console.WriteLine(max);
            Console.Read();
        }
    }