public ModMatrix invert()
{
ModMatrix mi = new ModMatrix(Dimension, Modulus);
BigInteger di = BigIntegerHelper.ModInverse(det(), Modulus);
for (int y = 0; y < Dimension; y++)
{
for (int x = 0; x < Dimension; x++)
{
int sign = 1 - 2 * ((x + y) % 2); // sign = (-1) ^ (x+y)
mi[x, y] = (((sign * di * minor(y, x)) % Modulus) + Modulus) % Modulus;
}
}
return(mi);
}
private static Stack <TOKEN> Scan(string expr)
{
TOKEN t = new TOKEN();
int startIndex = 0;
if (expr == "")
{
return(new Stack <TOKEN>());
}
switch (expr[0])
{
case ' ':
return(Scan(expr.Substring(1)));
case '(':
t.ttype = TOKEN.Ttype.BRACKETOPEN;
startIndex = 1;
break;
case ')':
t.ttype = TOKEN.Ttype.BRACKETCLOSE;
startIndex = 1;
break;
case '+':
t.ttype = TOKEN.Ttype.PLUS;
startIndex = 1;
break;
case '-':
t.ttype = TOKEN.Ttype.MINUS;
startIndex = 1;
break;
case '*':
if (expr.Length > 1 && expr[1] == '*')
{
t.ttype = TOKEN.Ttype.POW;
startIndex = 2;
}
else
{
t.ttype = TOKEN.Ttype.MULTIPLY;
startIndex = 1;
}
break;
case '/':
t.ttype = TOKEN.Ttype.DIVIDE;
startIndex = 1;
break;
case '^':
t.ttype = TOKEN.Ttype.POW;
startIndex = 1;
break;
case '!':
t.ttype = TOKEN.Ttype.EXCLAMATION;
startIndex = 1;
break;
case '%':
t.ttype = TOKEN.Ttype.PERCENT;
startIndex = 1;
break;
case ',':
t.ttype = TOKEN.Ttype.COMMA;
startIndex = 1;
break;
default:
Match m;
bool found = false;
foreach (var f in prefixFunctions)
{
m = Regex.Match(expr, "^" + f.Value.pattern, RegexOptions.IgnoreCase);
if (m.Success)
{
t.ttype = TOKEN.Ttype.FUNCTION;
t.function = f.Key;
startIndex = m.Length;
found = true;
break;
}
}
if (found)
{
break;
}
if (Regex.IsMatch(expr, "^mod", RegexOptions.IgnoreCase))
{
t.ttype = TOKEN.Ttype.MOD;
startIndex = 3;
break;
}
// try to parse as hexadecimal, decimal, octal or binary number
m = Regex.Match(expr, @"^([0-9a-z]+)\(([0-9]+)\)", RegexOptions.IgnoreCase);
if (m.Success)
{
int basis = int.Parse(m.Groups[2].Value);
t.integer = Parse(m.Groups[1].Value, basis);
t.ttype = TOKEN.Ttype.INTEGER;
startIndex = m.Groups[0].Value.Length;
break;
}
m = Regex.Match(expr, @"^[#hx]([0-9a-f]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
//t.integer = BigInteger.Parse(m.Groups[1].Value, NumberStyles.AllowHexSpecifier);
t.integer = BigIntegerHelper.Parse(m.Groups[1].Value, 16);
t.ttype = TOKEN.Ttype.INTEGER;
startIndex = m.Groups[0].Value.Length;
break;
}
m = Regex.Match(expr, @"^([0-9]+)");
if (m.Success)
{
t.integer = BigInteger.Parse(m.Groups[1].Value);
t.ttype = TOKEN.Ttype.INTEGER;
startIndex = m.Groups[0].Value.Length;
break;
}
m = Regex.Match(expr, @"^o([0-7]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
t.integer = BigIntegerHelper.Parse(m.Groups[1].Value, 8);
t.ttype = TOKEN.Ttype.INTEGER;
startIndex = m.Groups[0].Value.Length;
break;
}
m = Regex.Match(expr, @"^b([01]+)", RegexOptions.IgnoreCase);
if (m.Success)
{
t.integer = BigIntegerHelper.Parse(m.Groups[1].Value, 2);
t.ttype = TOKEN.Ttype.INTEGER;
startIndex = m.Groups[0].Value.Length;
break;
}
if (expr[0] == '#')
{
t.ttype = TOKEN.Ttype.HASH;
startIndex = 1;
break;
}
throw new ParseException("parsing failed at character " + expr[0]);
}
Stack <TOKEN> st = Scan(expr.Substring(startIndex));
st.Push(t);
return(st);
}