public SnailNumber Split()
{
if (A > 9)
{
Left = MakeSplit(A, this);
A = 0;
return(Left);
}
SnailNumber sn;
if (Left != null)
{
sn = Left.Split();
if (sn != null)
{
return(sn);
}
}
if (B > 9)
{
Right = MakeSplit(B, this);
B = 0;
return(Right);
}
if (Right != null)
{
sn = Right.Split();
if (sn != null)
{
return(sn);
}
}
return(null);
}
public static SnailNumber Builder(string line)
{
using StringReader sreader = new StringReader(line);
SnailNumber root = Parser(sreader, false);
return(root);
}
public SnailNumber FindExplode(int level)
{
if (level == 4)
{
return(this);
}
++level;
SnailNumber explode = null;
if (Left != null)
{
explode = Left.FindExplode(level);
if (explode != null)
{
return(explode);
}
}
if (Right != null)
{
explode = Right.FindExplode(level);
if (explode != null)
{
return(explode);
}
}
return(null);
}
public SnailNumber ExplodeRight(int val, SnailNumber explode)
{
if (Parent == null)
{
return(null);
}
SnailNumber sn;
if (this == Parent.Right)
{
sn = Parent.ExplodeRight(val, explode);
if (sn == null)
{
if (this.Right == explode)
{
// not found set B to 0.
B = 0;
return(this);
}
}
return(sn);
}
else
{
sn = Parent.AddLeft(val, this);
return(sn);
}
}
public SnailNumber MakeSplit(int val, SnailNumber parent)
{
SnailNumber splitSn = new SnailNumber();
splitSn.Parent = parent;
splitSn.A = val / 2;
splitSn.B = (val / 2) + val % 2;
return(splitSn);
}
public SnailNumber Add(SnailNumber b)
{
SnailNumber sn = new SnailNumber();
sn.Left = this;
this.Parent = sn;
sn.Right = b;
sn.Right.Parent = sn;
return(sn);
}
public SnailNumber Explode()
{
SnailNumber explode = FindExplode(0);
if (explode != null)
{
explode.ExplodeLeft(explode.A, explode);
explode.ExplodeRight(explode.B, explode);
explode.RemoveMe();
}
return(explode);
}
public void Reduce()
{
SnailNumber explode = null;
SnailNumber split = null;
do
{
explode = Explode();
if (explode == null)
{
split = Split();
}
} while (explode != null || split != null);
}
public SnailNumber AddLeft(int val, SnailNumber snr)
{
if (Left != null)
{
if (Left == snr)
{
if (Right == null)
{
B += val;
return(this);
}
return(Right.AddLeft(val, snr));
}
return(Left.AddLeft(val, snr));
}
// Left is null found most Left most to the right of the exploder
A += val;
return(this);
}
public SnailNumber AddRight(int val, SnailNumber snr)
{
if (Right != null)
{
if (Right == snr)
{
if (Left == null)
{
A += val;
return(this);
}
return(Left.AddRight(val, snr));
}
return(Right.AddRight(val, snr));
}
// right is null found most right to the left of the exploder
B += val;
return(this);
}
public static SnailNumber Parser(StringReader srdr, bool readLeftBrace)
{
SnailNumber sn = new SnailNumber();
bool left = true;
while (srdr.Peek() != -1)
{
var ch = (char)srdr.Read();
switch (ch)
{
case '[':
if (readLeftBrace)
{
// start of a new snailnumber
if (left)
{
sn.Left = Parser(srdr, true);
sn.Left.Parent = sn;
left = false;
}
else
{
sn.Right = Parser(srdr, true);
sn.Right.Parent = sn;
}
}
else
{
readLeftBrace = true;
}
break;
case ']':
return(sn);
case ',':
left = false;
break;
case ' ':
break;
default:
// digits?
if (char.IsDigit(ch))
{
int val = (int)ch - '0';
if ((srdr.Peek() != -1) && (char.IsDigit((char)srdr.Peek())))
{
// debugging tests
val = (val * 10) + (int)((char)srdr.Read() - '0');
}
if (left)
{
sn.A = val;
left = false;
}
else
{
sn.B = val;
}
}
else
{
throw new ArgumentException($"Char: {ch} is not expected");
}
break;
}
}
return(sn);
}
