public static ArbitraryNumber Sub(ArbitraryNumber a, ArbitraryNumber b)
{
if (a.IsNegative)
{
if (b.IsNegative)
{
return(-SubstractPositives(-a, -b));
}
else
{
return(-AddPositives(-a, b));
}
}
else
{
if (b.IsNegative)
{
return(AddPositives(a, -b));
}
else
{
return(SubstractPositives(a, b));
}
}
}
private static ArbitraryNumber Abs(ArbitraryNumber num)
{
var abs = new ArbitraryNumber(num);
abs.IsNegative = false;
return(abs);
}
private static ArbitraryNumber MultBySingleDigit(ArbitraryNumber an, int digit)
{
Guard.Requires(0 <= digit && digit < 10, $"Requires 0 <= {nameof(digit)} < 10, but actual value was {digit}");
var result = new ArbitraryNumber();
int carryOver = 0;
foreach (int d in an.Digits.AsEnumerable().Reverse())
{
int mul = d * digit + carryOver;
int val = mul % 10;
carryOver = (mul - val) / 10;
result.Digits.Insert(0, val);
}
while (carryOver > 0)
{
int val = carryOver % 10;
result.Digits.Insert(0, val);
carryOver = (carryOver - val) / 10;
}
result.DecimalsCount = an.DecimalsCount;
Trim(result);
return(result);
}
private static void InsertdecimalShift(ArbitraryNumber intermediateResult, int decimalShift)
{
for (int i = 0; i < decimalShift; i++)
{
intermediateResult.Digits.Insert(0, 0);
}
}
public static ArbitraryNumber Mult(ArbitraryNumber a, ArbitraryNumber b)
{
if (a.IsNegative == b.IsNegative)
{
return(MultPositives(Abs(a), Abs(b)));
}
else
{
return(-MultPositives(Abs(a), Abs(b)));
}
}
private static void AlignFractionalDigits(ArbitraryNumber num1, ArbitraryNumber num2)
{
if (num1.FractionalPart.Count == num2.FractionalPart.Count)
{
return;
}
ArbitraryNumber lessFractional = Selector.Min(an => an.FractionalPart.Count, num1, num2);
ArbitraryNumber mostFractional = Selector.Max(an => an.FractionalPart.Count, num1, num2);
lessFractional.Digits.AddRange(Enumerable.Repeat(0, mostFractional.FractionalPart.Count - lessFractional.FractionalPart.Count));
lessFractional.DecimalsCount += mostFractional.FractionalPart.Count - lessFractional.FractionalPart.Count;
}
private static void Trim(ArbitraryNumber num)
{
if (num.DecimalsCount > 0)
{
int initialDigitsCount = num.Digits.Count;
num.Digits.TrimRight(0, num.DecimalsCount);
num.DecimalsCount -= initialDigitsCount - num.Digits.Count;
}
num.Digits.TrimLeft(0);
if (!num.Digits.Any())
{
num.DecimalsCount = 0;
}
}
private static ArbitraryNumber SubstractPositives(ArbitraryNumber a, ArbitraryNumber b)
{
var num1 = new ArbitraryNumber(a);
var num2 = new ArbitraryNumber(b);
AlignFractionalDigits(num1, num2);
var result = new ArbitraryNumber();
var enumerator = new ParallelEnumerator <int>(num1.Digits.AsEnumerable().Reverse(), num2.Digits.AsEnumerable().Reverse());
int carryOver = 0;
while (enumerator.Next())
{
int val1 = enumerator.Current[0];
int val2 = enumerator.Current[1];
int sub = val1 - val2 - carryOver;
int val = 0;
if (sub < 0)
{
val = 10 + sub;
carryOver = 1;
}
else
{
val = sub;
carryOver = 0;
}
result.Digits.Insert(0, val);
}
if (carryOver > 0)
{
result.Digits.Insert(0, carryOver);
result.IsNegative = true;
}
result.DecimalsCount = num1.DecimalsCount;
Trim(result);
return(result);
}
private static ArbitraryNumber MultPositives(ArbitraryNumber arbitraryNumber1, ArbitraryNumber arbitraryNumber2)
{
var result = new ArbitraryNumber();
var an = new ArbitraryNumber(arbitraryNumber1);
foreach (int digit in arbitraryNumber2.Digits.AsEnumerable().Reverse())
{
result += MultBySingleDigit(an, digit);
an.Digits.Add(0);
}
result.DecimalsCount += arbitraryNumber2.DecimalsCount;
Trim(result);
return(result);
}
public static ArbitraryNumber Pow(this ArbitraryNumber a, int pow)
{
if (pow == 0)
{
return(1);
}
ArbitraryNumber result = 1;
for (int i = 0; i < pow; i++)
{
result *= a;
}
Trim(result);
return(pow > 0 ? result : 1 / result);
}
public static ArbitraryNumber Min(ArbitraryNumber a, ArbitraryNumber b)
{
if (a.IntegerPart.Count < b.IntegerPart.Count)
{
return(a);
}
if (a.IntegerPart.Count > b.IntegerPart.Count)
{
return(b);
}
if (a.Digits[0] <= b.Digits[0])
{
return(a);
}
else
{
return(b);
}
}
private static ArbitraryNumber AddPositives(ArbitraryNumber a, ArbitraryNumber b)
{
var num1 = new ArbitraryNumber(a);
var num2 = new ArbitraryNumber(b);
AlignFractionalDigits(num1, num2);
var result = new ArbitraryNumber();
var enumerator = new ParallelEnumerator <int>(num1.Digits.AsEnumerable().Reverse(), num2.Digits.AsEnumerable().Reverse());
int carryOver = 0;
while (enumerator.Next())
{
int val1 = enumerator.Current[0];
int val2 = enumerator.Current[1];
int added = val1 + val2 + carryOver;
int val = added % 10;
carryOver = (added - val) / 10;
result.Digits.Insert(0, val);
}
if (carryOver > 0)
{
result.Digits.Insert(0, carryOver);
}
result.DecimalsCount = num1.DecimalsCount;
Trim(result);
return(result);
}
public static ArbitraryNumber Pow(ArbitraryNumber a, ArbitraryNumber pow)
{
throw new System.NotImplementedException();
}
public ArbitraryNumber(ArbitraryNumber other) : this(new List <int>(other?.Digits ?? new List <int>()), other?.DecimalsCount ?? 0)
{
}