Prefix Sums - MinAvgTwoSlice

Here is another codility problem solution from the codility lessons (MinAvgTwoSlice-Find the minimal average of any slice containing at least two elements.) due to the copy rights I can't copy the content of the problem here so to view the problem description click here.

class Solution {
	public int solution(int[] A) {
		long min = Long.MAX_VALUE;
		int index = -1;
		//we have A+B/2 to be comapred with A+B+C/3
		//to make things easiler we are going to multuply both side with 6


		for (int i = 0; i < A.length - 2; i++) {

			long res1 = ((A[i] + A[i + 1])) * 3;
			long res2 = ((A[i] + A[i + 1] + A[i + 2])) * 2;



			long minRes = Math.min(res1, res2);

			if (minRes < min) {
				min = minRes;
				index = i;
			}

		}
		if ((A[A.length - 2] + A[A.length - 1]) * 3 < min) {
			return A.length - 2;
		}

		return index;
	}
}