public void Split()
{
//To split a regular number, replace it with a pair;
//the left element of the pair should be the regular number divided by two and rounded down,
//while the right element of the pair should be the regular number divided by two and rounded up.
//For example, 10 becomes [5,5], 11 becomes [5,6], 12 becomes [6,6], and so on.
var half = Math.DivRem(Number, 2, out int remainder);
Number = half;
var right = new SnailfishRegularNumber(half + remainder);
var currentParent = Parent;
var currenPosition = NumberPosition;
SnailfishNumberPair replacement = new SnailfishNumberPair(this, right);
replacement.Parent = currentParent;
replacement.NumberPosition = currenPosition;
if (currenPosition == PairPosition.Left)
{
currentParent.LeftNumber = replacement;
}
else
{
currentParent.RightNumber = replacement;
}
}
public void Explode()
{
//To explode a pair, the pair's left value is added to the first regular number to the left of the exploding pair (if any),
//and the pair's right value is added to the first regular number to the right of the exploding pair (if any).
//Exploding pairs will always consist of two regular numbers. Then, the entire exploding pair is replaced with the regular number 0.
//Change number to the left
var current = this;
while (current != null)
{
if (current.NumberPosition == PairPosition.Right)
{
current.Parent.LeftNumber.AddToRight(((SnailfishRegularNumber)LeftNumber).Number);
break;
}
current = current.Parent;
}
//Change number to the right
current = this;
while (current != null)
{
if (current.NumberPosition == PairPosition.Left)
{
current.Parent.RightNumber.AddToLeft(((SnailfishRegularNumber)RightNumber).Number);
break;
}
current = current.Parent;
}
//Replace this pair with a zero
var currentParent = Parent;
SnailfishRegularNumber replacement = new SnailfishRegularNumber(0)
{
Parent = currentParent
};
if (NumberPosition == PairPosition.Left)
{
replacement.NumberPosition = PairPosition.Left;
replacement.Parent.LeftNumber = replacement;
}
else
{
replacement.NumberPosition = PairPosition.Right;
replacement.Parent.RightNumber = replacement;
}
}
internal static SnailfishNumberPair ParseNumber(string numberString)
{
SnailfishNumberPair currentPair = null;
Stack <SnailfishNumberPair> pairs = new Stack <SnailfishNumberPair>();
foreach (var letter in numberString)
{
switch (letter)
{
case '[':
//add pair
if (currentPair != null)
{
pairs.Push(currentPair);
}
currentPair = new SnailfishNumberPair();
var parent = pairs.Count > 0 ? pairs.Peek() : null;
if (parent != null)
{
currentPair.Parent = parent;
if (parent?.LeftNumber == null)
{
parent.SetLeft(currentPair);
}
else
{
parent.SetRight(currentPair);
}
}
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
var number = new SnailfishRegularNumber(Convert.ToInt32(letter.ToString()));
if (currentPair?.LeftNumber == null)
{
currentPair.SetLeft(number);
}
else
{
currentPair.SetRight(number);
}
break;
case ']':
currentPair = pairs.Count > 0 ? pairs.Pop() : currentPair;
break;
case ',':
//do nothing, logic is in set number
default:
break;
}
}
return(currentPair);
}