private static BcdNumber Add(BcdNumber f, BcdNumber s)
{
if (f._neg != s._neg)
{
if (s._neg)
{
return(Sub(f, -s));
}
else
{
return(Sub(s, -f));
}
}
Align(ref f, ref s);
var len = Math.Max(f._len, s._len);
var digits = new byte[len];
SortSwap(ref f, ref s);
SumDigits(f._digits, 0, s._digits, 0, ref digits, 0, out int pos);
var result = new BcdNumber
{
_int = f._int && s._int,
_neg = f._neg && s._neg,
_digits = digits,
_len = digits.Length,
_plen = f._plen
};
return(result);
}
public static BcdNumber operator -(BcdNumber n)
{
var result = new BcdNumber(n);
result._neg = !result._neg;
return(result);
}
private static void SortSwap(ref BcdNumber f, ref BcdNumber s)
{
if (s._len > f._len)
{
var t = s;
s = f;
f = t;
}
}
public BcdNumber(BcdNumber n)
{
_neg = n._neg;
_int = n._int;
_digits = new byte[n._len];
Array.Copy(n._digits, _digits, n._len);
_len = n._len;
_plen = n._plen;
}
private static BcdNumber Mul(BcdNumber f, BcdNumber s)
{
Align(ref f, ref s);
var isInt = f._int && s._int;
var neg = f._neg != s._neg;
var plen = f._plen + s._plen;
SortSwap(ref f, ref s);
var cached = new Dictionary <byte, MulByteCacheEntry>();
var sumArray = new Queue <byte[]>();
for (var i = 0; i < s._len; ++i)
{
var mul = s._digits[i];
byte[] r;
if (cached.TryGetValue(mul, out MulByteCacheEntry fromCache))
{
r = new byte[fromCache.Len + i];
Array.Copy(fromCache.Data, fromCache.Offset, r, i, fromCache.Len);
sumArray.Enqueue(r);
}
else
{
var k = i;
var mulByte = MulByte(f._digits, mul, k);
cached.Add(mul, new MulByteCacheEntry()
{
Data = mulByte, Offset = k
});
sumArray.Enqueue(mulByte);
}
}
cached.Clear();
var result = SumQueue(sumArray);
return(new BcdNumber()
{
_digits = result,
_len = result.Length,
_plen = plen,
_neg = neg,
_int = isInt
}.Trim());
}
private BcdNumber ShiftLeft(int amount)
{
if (amount == 0)
{
return(this);
}
if (IsZero())
{
return(Zero);
}
var plen = _plen - amount;
if (plen >= 0)
{
var result = new BcdNumber(this);
result._plen = plen;
result._int = plen == 0;
return(result.Trim());
}
amount -= _plen;
var noZeroesLen = _len;
while (_digits[noZeroesLen - 1] == 0 && _len > 1)
{
--noZeroesLen;
}
var nLen = noZeroesLen + amount;
var digits = new byte[nLen];
Array.Copy(_digits, 0, digits, amount, noZeroesLen);
return(new BcdNumber()
{
_digits = digits,
_int = true,
_plen = 0,
_len = _len + amount,
_neg = _neg
});
}
static BcdNumber()
{
Zero = new BcdNumber("0");
One = new BcdNumber("1");
}
private static void Align(ref BcdNumber f, ref BcdNumber s)
{
if (f._plen == s._plen)
{
return;
}
bool isInt1 = f._int;
int len1 = f._len;
int plen1 = f._plen;
var digits1 = new List <byte>(len1);
BcdNumber result1 = null;
bool isInt2 = s._int;
int len2 = s._len;
int plen2 = s._plen;
var digits2 = new List <byte>(len2);
BcdNumber result2 = null;
if (f._plen > s._plen)
{
var c = f._plen - s._plen;
var zeros = Enumerable.Repeat <byte>(0, c);
plen2 += c;
len2 += c;
isInt2 = false;
digits2.AddRange(zeros);
digits2.AddRange(s._digits);
result1 = f;
}
else
{
var c = s._plen - f._plen;
var zeros = Enumerable.Repeat <byte>(0, c);
plen1 += c;
len1 += c;
isInt1 = false;
digits1.AddRange(zeros);
digits1.AddRange(f._digits);
result2 = s;
}
if (result1 == null)
{
result1 = new BcdNumber
{
_digits = digits1.ToArray(),
_neg = f._neg,
_int = isInt1,
_len = len1,
_plen = plen1
};
}
if (result2 == null)
{
result2 = new BcdNumber
{
_digits = digits2.ToArray(),
_neg = s._neg,
_int = isInt2,
_len = len2,
_plen = plen2
};
}
f = result1;
s = result2;
}
private static BcdNumber Div(BcdNumber f, BcdNumber s)
{
if (s == Zero)
{
throw new DivideByZeroException();
}
var neg = f._neg != s._neg;
var plen = 0;
var digits = new byte[f._len];
var dPos = 0;
var maxPLen = Math.Max(f._plen, s._plen);
if (maxPLen > 0)
{
f = f.ShiftLeft(maxPLen);
s = s.ShiftLeft(maxPLen);
}
do
{
var shiftFix = f._digits[f._len - 1] < s._digits[s._len - 1] ? 1 : 0;
if (f > s)
{
var shift = f._len - s._len - shiftFix;
s <<= shift;
dPos = +shift;
}
else if (f < s)
{
var shift = s._len - f._len + shiftFix;
f <<= shift;
dPos -= shift;
}
if (dPos < 0)
{
var l = -dPos;
Array.Resize(ref digits, digits.Length + l);
Array.Copy(digits, 0, digits, l, digits.Length - l);
for (var i = 0; i < l; ++i)
{
digits[i] = 0;
}
plen += l;
dPos = 0;
}
if (digits.Length <= dPos)
{
Array.Resize(ref digits, dPos + 1);
}
var r = 0;
while (f >= s)
{
f -= s;
++r;
}
digits[dPos] = (byte)r;
} while (!f.IsZero() && plen < MaxResolution);
return(new BcdNumber()
{
_digits = digits,
_len = digits.Length,
_int = plen == 0,
_neg = neg,
_plen = plen
}.Trim());
}
private static BcdNumber Sub(BcdNumber f, BcdNumber s)
{
if (f._neg != s._neg)
{
if (s._neg)
{
return(Add(f, -s));
}
else
{
return(-Add(-f, s));
}
}
if (f._neg)
{
var t = -f;
f = -s;
s = t;
}
var neg = false;
var cmp = Compare(f, s);
if (cmp == 0)
{
return(Zero);
}
if (cmp < 0)
{
neg = true;
var t = f;
f = s;
s = t;
}
Align(ref f, ref s);
var digits = new byte[f._len];
var carry = 0;
var i = 0;
for (; i < s._len; ++i)
{
var r = f._digits[i] - s._digits[i] - carry;
if (r < 0)
{
r += 10;
carry = 1;
}
else
{
carry = 0;
}
digits[i] = (byte)r;
}
for (; i < f._len; ++i)
{
var r = f._digits[i] - carry;
if (r < 0)
{
r += 10;
}
carry = 0;
digits[i] = (byte)r;
}
i = digits.Length - 1;
while (i >= 0 && digits[i] == 0)
{
--i;
}
if (i != digits.Length - 1)
{
Array.Resize(ref digits, digits.Length - (digits.Length - i - 1));
}
return(new BcdNumber()
{
_digits = digits,
_len = digits.Length,
_int = f._int && s._int,
_neg = neg,
_plen = f._plen
}.Trim());
}
public static int Compare(BcdNumber f, BcdNumber s)
{
if (ReferenceEquals(f, null))
{
return(-1);
}
if (ReferenceEquals(s, null))
{
return(1);
}
if (f._neg != s._neg)
{
return(f._neg ? -1 : 1);
}
var n = f._neg;
var fIntLen = f._len - f._plen;
var sIntLen = s._len - s._plen;
if (fIntLen != sIntLen)
{
if (n)
{
return(fIntLen > sIntLen ? -1 : 1);
}
else
{
return(fIntLen > sIntLen ? 1 : -1);
}
}
var intLen = sIntLen;
for (var i = intLen - 1; i >= 0; --i)
{
if (f._digits[i + f._plen] == s._digits[i + s._plen])
{
continue;
}
if (n)
{
return(f._digits[i + f._plen] > s._digits[i + s._plen] ? -1 : 1);
}
else
{
return(f._digits[i + f._plen] > s._digits[i + s._plen] ? 1 : -1);
}
}
// integer parts are the same
var pLen = Math.Min(f._plen, s._plen);
for (var i = pLen; i >= 0; --i)
{
if (f._digits[i] == s._digits[i])
{
continue;
}
if (n)
{
return(f._digits[i] == s._digits[i] ? -1 : 1);
}
else
{
return(f._digits[i] == s._digits[i] ? 1 : -1);
}
}
// shared plen frac parts are the same
if (f._plen == s._plen)
{
return(0);
}
if (n)
{
return(f._plen > s._plen ? -1 : 1);
}
else
{
return(f._plen > s._plen ? 1 : -1);
}
}