public static BigInteger operator -(BigInteger a, BigInteger b)
{
BigInteger nb = new BigInteger(!b.IsPositive, b.Magnitude);
return a + nb;
}
public static int Compare(BigInteger a, BigInteger b)
{
if (a.Magnitude == b.Magnitude) {
if (a.Magnitude == 0) return 0;
if (a.IsPositive == b.IsPositive) return 0;
}
if (a.IsPositive) {
if (b.IsPositive) {
return (a.Magnitude > b.Magnitude) ? 1 : -1;
} else {
return 1;
}
} else {
if (b.IsPositive) {
return -1;
} else {
return (a.Magnitude > b.Magnitude) ? -1 : 1;
}
}
}