/** @see BigInteger#doubleValue() */
internal static double bigInteger2Double(BigInteger val)
{
// val.bitLength() < 64
if ((val.numberLength < 2)
|| ((val.numberLength == 2) && (val.digits[1] > 0))) {
return val.longValue();
}
// val.bitLength() >= 33 * 32 > 1024
if (val.numberLength > 32) {
return ((val.sign > 0) ? double.PositiveInfinity
: double.NegativeInfinity);
}
return Convert.ToDouble(val.ToString());
}
internal static String bigInteger2String(BigInteger val, int radix)
{
int sign = val.sign;
int numberLength = val.numberLength;
int[] digits = val.digits;
if (sign == 0) {
return "0"; //$NON-NLS-1$
}
if (numberLength == 1) {
int highDigit = digits[numberLength - 1];
long v = highDigit & 0xFFFFFFFFL;
if (sign < 0) {
v = -v;
}
return Convert.ToString(v, radix);
}
if ((radix == 10) || (radix < 0)
|| (radix > 26)) {
return val.ToString();
}
double bitsForRadixDigit;
bitsForRadixDigit = Math.Log(radix) / Math.Log(2);
int resLengthInChars = (int) (val.abs().bitLength() / bitsForRadixDigit + ((sign < 0) ? 1
: 0)) + 1;
char[] result = new char[resLengthInChars];
int currentChar = resLengthInChars;
int resDigit;
if (radix != 16) {
int[] temp = new int[numberLength];
Array.Copy(digits, 0, temp, 0, numberLength);
int tempLen = numberLength;
int charsPerInt = digitFitInInt[radix];
int i;
// get the maximal power of radix that fits in int
int bigRadix = bigRadices[radix - 2];
while (true) {
// divide the array of digits by bigRadix and convert remainders
// to characters collecting them in the char array
resDigit = Division.divideArrayByInt(temp, temp, tempLen,
bigRadix);
int previous = currentChar;
do {
result[--currentChar] = Convert.ToString(resDigit % radix, radix)[0];
} while (((resDigit /= radix) != 0) && (currentChar != 0));
int delta = charsPerInt - previous + currentChar;
for (i = 0; i < delta && currentChar > 0; i++) {
result[--currentChar] = '0';
}
for (i = tempLen - 1; (i > 0) && (temp[i] == 0); i--) {
;
}
tempLen = i + 1;
if ((tempLen == 1) && (temp[0] == 0)) { // the quotient is 0
break;
}
}
} else {
// radix == 16
for (int i = 0; i < numberLength; i++) {
for (int j = 0; (j < 8) && (currentChar > 0); j++) {
resDigit = digits[i] >> (j << 2) & 0xf;
result[--currentChar] = Convert.ToString(resDigit % radix, 16)[0];
}
}
}
while (result[currentChar] == '0') {
currentChar++;
}
if (sign == -1) {
result[--currentChar] = '-';
}
return new String(result, currentChar, resLengthInChars - currentChar);
}
