public static MutableInteger SetModularInverse(this MutableInteger c, MutableInteger a, MutableInteger b, MutableIntegerStore store)
{
var p = store.Allocate().Set(a);
var q = store.Allocate().Set(b);
var x0 = store.Allocate().Set(1);
var x1 = store.Allocate().Set(0);
var quotient = store.Allocate();
var remainder = store.Allocate();
var product = store.Allocate();
while (!q.IsZero)
{
remainder.Set(p).ModuloWithQuotient(q, quotient);
var tmpp = p;
p = q;
q = tmpp.Set(remainder);
var tmpx = x1;
x1 = x0.Subtract(product.SetProduct(quotient, x1));
x0 = tmpx;
}
c.Set(x0);
if (c.Sign == -1)
{
c.Add(b);
}
store.Release(p);
store.Release(q);
store.Release(x0);
store.Release(x1);
store.Release(quotient);
store.Release(remainder);
return(c);
}
public static MutableInteger SetModularInversePowerOfTwoModulus(this MutableInteger c, MutableInteger d, int n, MutableIntegerStore store)
{
// See 9.2 in: http://gmplib.org/~tege/divcnst-pldi94.pdf
c.Set(d);
var two = store.Allocate().Set(2);
var reg1 = store.Allocate();
var reg2 = store.Allocate();
for (int m = 3; m < n; m *= 2)
{
reg1.Set(c);
reg2.SetProduct(reg1, d);
reg2.Mask(n);
reg2.SetDifference(two, reg2);
c.SetProduct(reg1, reg2);
c.Mask(n);
}
if (c.Sign == -1)
{
c.Add(reg1.Set(1).LeftShift(n));
}
store.Release(two);
store.Release(reg1);
store.Release(reg2);
return(c);
}
public void RemoveParty(int partySize)
{
remainingCapacity.Add(partySize);
}