private NailNumber CheckExplode(ref bool explode, int depth = 0)
{
if (IsNumber)
{
return(this);
}
if (depth == 4)
{
// too deep
explode = true;
var node = new NailNumber(0);
if (_left._previous != null)
{
_left._previous._value += _left._value;
node.SetPrevious(_left._previous);
_left._previous.SetNext(node);
}
if (_right._next == null)
{
return(node);
}
_right._next._value += _right._value;
node.SetNext(_right._next);
_right._next.SetPrevious(node);
return(node);
}
_left = _left.CheckExplode(ref explode, depth + 1);
_right = _right.CheckExplode(ref explode, depth + 1);
return(this);
}
public NailNumber Add(NailNumber a)
{
var result = new NailNumber(new NailNumber(this), new NailNumber(a));
bool redo;
do
{
redo = false;
result.CheckExplode(ref redo);
if (!redo)
{
result.CheckSplit(ref redo);
}
} while (redo);
return(result);
}