public SnailNum Add(SnailNum other)
{
var newHead = Token.GetToken('[');
var comma = Token.GetToken(',');
var close = Token.GetToken(']');
newHead.Right = _head;
_head.Left = newHead;
var tail = _head.Tail();
tail.Right = comma;
comma.Left = tail;
comma.Right = other._head;
other._head.Left = comma;
tail = other._head.Tail();
tail.Right = close;
close.Left = tail;
var newSN = new SnailNum(newHead);
newSN.Reduce();
return(newSN);
}
public ulong Magnitiude()
{
var sn = new SnailNum(this.ToString());
while (true)
{
var n = sn._head;
if (IsSimplePair(n) && n.Left == null)
{
return(n.Right.Val * 3 + n.Right.Right.Right.Val * 2);
}
while (n.Right != null)
{
if (IsSimplePair(n))
{
var left = n.Right.Val;
var right = n.Right.Right.Right.Val;
var m = n.Right;
m.Val = left * 3 + right * 2;
n.Left.Right = m;
m.Right = n.Right.Right.Right.Right.Right; // perfectly ordinary double linked list code...
}
n = n.Right;
}
}
}
void DoSplit(Token t)
{
float tval = t.Val;
int leftVal = (int)Math.Floor(tval / 2);
int rightVal = (int)Math.Ceiling(tval / 2);
var newPair = new SnailNum($"[{(char)(leftVal +'0')},{(char)(rightVal +'0')}]");
t.Left.Right = newPair._head;
newPair._head.Left = t.Left;
var tail = newPair._head.Tail();
tail.Right = t.Right;
tail.Right.Left = tail;
}
public void Solve()
{
var lines = File.ReadAllLines("inputs/day18.txt");
var res = new SnailNum(lines[0]);
for (int j = 1; j < lines.Length; j++)
{
res = res.Add(new SnailNum(lines[j]));
}
Console.WriteLine($"P1: {res.Magnitiude()}");
ulong greatest = 0;
for (int j = 0; j < lines.Length - 1; j++)
{
for (int k = j + 1; k < lines.Length - 2; k++)
{
var sn0 = new SnailNum(lines[j]);
var sn1 = new SnailNum(lines[k]);
try
{
ulong mn = sn0.Add(sn1).Magnitiude();
if (mn > greatest)
{
greatest = mn;
}
sn0 = new SnailNum(lines[j]);
sn1 = new SnailNum(lines[k]);
mn = sn1.Add(sn0).Magnitiude();
if (mn > greatest)
{
greatest = mn;
}
}
catch (Exception)
{
Console.WriteLine($"{j}, {k}");
Console.WriteLine(sn0);
Console.WriteLine(sn1);
}
}
}
Console.WriteLine($"P2: {greatest}");
}