Solution (100%) to MinAvgTwoSlice problem on Codility (https://codility.com/programmers/task/min_avg_two_slice)

MinAvgTwoSlice.java

/*
 * ABSOLUTELY NON-TRIVIAL (AND CERTAINLY NOT DOABLE WITHIN A SHORT TIME FRAME):
 * IT'S NECESSARY TO FIND OUT FIRST THAT ONLY SLICES OF LENGTH 2 OR 3 MATTER
 *
 * PROOF:
 * https://codesays.com/2014/solution-to-min-avg-two-slice-by-codility
 *
 * NOTE: THE USAGE OF "PREFIX-SUMS" IS NOT PURELY NECESSARY
 * (BUT IT WAS IN PLACE AT THE TIME I STILL BELIEVED THAT SLICES
 * OF ARBITRARY LENGTHS COULD BE INVOLVED...)
 */
 
class Solution
{
    public int solution(int[] A)
    {
        int N = A.length;
        int[] sums = new int[N + 1];
        
        for (int i = 0; i < N; i++)
        {
            sums[i + 1] = sums[i] + A[i];
        }
        
        float minAvg = Float.MAX_VALUE;
        int minSliceIndex = 0;
        
        for (int i = 0; i < N - 1; i++)
        {
            int i0 = i;
            int i1 = i + 1;
            float avg2 = (sums[i1 + 1] - sums[i0]) / 2.0f;
            
            if (avg2 < minAvg)
            {
                minAvg = avg2;
                minSliceIndex = i;
            }
            
            if (i < N - 2)
            {
                int i2 = i + 2;
                float avg3 = (sums[i2 + 1] - sums[i0]) / 3.0f;
                
                if (avg3 < minAvg)
                {
                    minAvg = avg3;
                    minSliceIndex = i;
                }
            }
        }
        
        return minSliceIndex;
    }
}