public static long SolvePart1Naive(IEnumerable <long> sequence, int preamble, ref List <long> list)
{
var window = new RingBuffer2D <long>(preamble, 1);
int seqNo = 0;
foreach (long input in sequence)
{
if (list != null)
{
list.Add(input);
}
if (seqNo >= preamble)
{
if (!HasPairSummingTo(window.Array, input))
{
return(input);
}
}
window.Write(0, 0, input);
window.XOffset++;
seqNo++;
}
return(-1);
}
public static long SolvePart1Ringbuffer(List <long> sequence, int preamble)
{
var window = new RingBuffer2D <long>(preamble, 1);
var sums = new RingBuffer2D <long>(preamble, preamble);
int seqNo = 0;
foreach (long input in sequence)
{
int num = Math.Min(seqNo, preamble);
if (seqNo >= preamble)
{
//Test against existing
if (!sums.Array.Contains(input))
{
return(input);
}
}
window.XOffset++;
sums.XOffset++;
sums.YOffset++;
//push right column:
if (seqNo >= preamble)
{
sums.SetRow(-1, 0);
}
for (int i = 0; i < num; i++)
{
long sum = input + window.Read(-i - 2, 0);
sums.Write(-1, -i - 1, sum);
}
window.Write(-1, 0, input);
seqNo++;
}
return(-1);
}
