static byte[] buildDH(DHPublicKey key) { DataByteOutputStream out = new DataByteOutputStream(); BigInteger p = key.getParams().getP(); BigInteger g = key.getParams().getG(); BigInteger y = key.getY(); int pLength, gLength, yLength; if (g.equals(TWO) && (p.equals(DHPRIME768) || p.equals(DHPRIME1024))) { pLength = 1; gLength = 0; } else { pLength = BigIntegerLength(p); gLength = BigIntegerLength(g); } yLength = BigIntegerLength(y); out.writeShort(pLength); if (pLength == 1) { if (p.bitLength() == 768) out.writeByte((byte) 1); else out.writeByte((byte) 2); } else out.writeBigInteger(p); out.writeShort(gLength); if (gLength > 0) out.writeBigInteger(g); out.writeShort(yLength); out.writeBigInteger(y); return out.toByteArray(); }
public static boolean check(long n, int p) { BigInteger P = BigInteger.TEN.pow(p), Q = BigInteger.TEN.pow(p - 1); BigInteger N = BigInteger.ONE, tmp = BigInteger.valueOf(2); while (n > 0) { if ((n % 2) == 1) { N = N.multiply(tmp); N = N.mod(P); } tmp = tmp.multiply(tmp); tmp = tmp.mod(P); n >>= 1; } N = N.divide(Q); if (N.equals(BigInteger.ONE) || N.equals(BigInteger.valueOf(2))) return true; else return false; }
void solve(int caseNum) { int n = in.nextInt(); BigInteger[] past = new BigInteger[n], d = new BigInteger[n]; for (int i = 0; i < n; i++) past[i] = new BigInteger(in.next()); Arrays.sort(past); for (int i = 0; i < n; i++) d[i] = past[i].subtract(past[0]); for (int i = 2; i < n; i++) d[i] = d[i].gcd(d[i - 1]); BigInteger gcd = d[n - 1], mod = past[0].mod(gcd); System.out.printf("Case #%d: ", caseNum); if (mod.equals(BigInteger.ZERO)) System.out.println(0); else System.out.println(gcd.subtract(mod)); }
public static void process() { Arrays.sort(bookHeight); BigInteger sum = BigInteger.valueOf(0L); BigInteger temp; int iCount = 0; for (int i = bookHeight.length - 1; i >= 0; i--) { sum = sum.add(BigInteger.valueOf((long) (bookHeight[i]))); temp = sum.max(b); iCount++; if (temp.equals(sum)) break; } System.out.print(iCount); }