public override void PartOne()
{
const int size = 256;
var nums = Enumerable.Range(0, size).Repeat(2).ToArray();
var current = 0;
var skip = 0;
foreach (var length in InputLine.Csv().Ints())
{
new Span <int>(nums, current, length).Reverse();
if (current + length > size)
{
Array.Copy(nums, size, nums, 0, current + length - size);
Array.Copy(nums, current, nums, current + size, size - current);
}
else
{
Array.Copy(nums, current, nums, current + size, length);
}
current = (current + length + skip) % size;
skip++;
}
var result = nums[0] * nums[1];
WriteLn(result);
}
public void Dance(CircularBuffer <int> buf)
{
var offset = 0;
foreach (var cmd in InputLine.Csv())
{
if (cmd[0] == 's')
{
offset -= int.Parse(cmd[1..]);
public override void PartOne()
{
var target = InputLine.Csv()
.Select(Pos3D.ParseHexDir)
.Aggregate(Pos3D.Add);
var result = target.HexDistance(Pos3D.Origin);
WriteLn(result);
}
public override void PartTwo()
{
var result = InputLine.Csv()
.Select(Pos3D.ParseHexDir)
.Scan(Pos3D.Add)
.Select(p => p.HexDistance(Pos3D.Origin))
.Max();
WriteLn(result);
}
public override void PartTwo()
{
var pos = InputLine.Csv().Ints().ToList();
var min = pos.Min();
var max = pos.Max() + 1;
Interval range = min..max;
var target = range.Min(i => pos.Select(p => Math.Abs(p - i)).Select(Algorithms.Sum1ToN).Sum());
WriteLn(target);
}
public IEnumerable <Pos> GetPoints()
{
var dir = Pos.Up;
var pos = Pos.Origin;
yield return(pos);
foreach (var move in InputLine.Csv(true))
{
dir = move[0] == 'L' ? dir.CounterClockwise() : dir.Clockwise();
pos += dir * move[1..].AsInt();
public long Steps(int count)
{
var counts = InputLine.Csv().Ints().Frequencies()
.ToArrayByIndex(9, pair => pair.Key, pair => (long)pair.Value);
var timers = new CircularBuffer <long>(counts);
for (var i = 0; i < count; i++)
{
timers.Offset++;
timers[6] += timers[8];
}
return(timers.Unordered().Sum());
}
public override void PartTwo()
{
var program = InputLine.Csv().Longs().ToArray();
foreach (var sequence in Algorithms.Sequences(2, 100, true))
{
var noun = sequence[0];
var verb = sequence[1];
var c = new Computer(program.ToArray())
{
[1] = noun, [2] = verb
};
c.Execute();
if (c[0] == 19690720)
{
WriteLn(100 * noun + verb);
return;
}
}
WriteLn("None");
}