// ceil(199*index/2).
    if (index % 2 == 0) {
      int position = IntMath.divide(199 * index, 2, UNNECESSARY);
      return PSEUDORANDOM_DATASET_SORTED.get(position);
    } else {
      int positionFloor = IntMath.divide(199 * index, 2, FLOOR);
      int positionCeil = IntMath.divide(199 * index, 2, CEILING);
      double lowerValue = PSEUDORANDOM_DATASET_SORTED.get(positionFloor);

    // ceil(199*index/2).
    if (index % 2 == 0) {
      int position = IntMath.divide(199 * index, 2, UNNECESSARY);
      return PSEUDORANDOM_DATASET_SORTED.get(position);
    } else {
      int positionFloor = IntMath.divide(199 * index, 2, FLOOR);
      int positionCeil = IntMath.divide(199 * index, 2, CEILING);
      double lowerValue = PSEUDORANDOM_DATASET_SORTED.get(positionFloor);

    a >>= aTwos; // divide out all 2s
    int bTwos = Integer.numberOfTrailingZeros(b);
    b >>= bTwos; // divide out all 2s
    while (a != b) { // both a, b are odd
      // The key to the binary GCD algorithm is as follows:
      // Both a and b are odd. Assume a > b; then gcd(a - b, b) = gcd(a, b).
      // But in gcd(a - b, b), a - b is even and b is odd, so we can divide out powers of two.

          long expected =
              new BigDecimal(valueOf(p)).divide(new BigDecimal(valueOf(q)), 0, mode).longValue();
          long actual = LongMath.divide(p, q, mode);
          if (expected != actual) {
            failFormat("expected divide(%s, %s, %s) = %s; got %s", p, q, mode, expected, actual);
          }
        }
      }
    }
  }

  @GwtIncompatible // TODO

          long expected =
              new BigDecimal(valueOf(p)).divide(new BigDecimal(valueOf(q)), 0, mode).longValue();
          long actual = LongMath.divide(p, q, mode);
          if (expected != actual) {
            failFormat("expected divide(%s, %s, %s) = %s; got %s", p, q, mode, expected, actual);
          }
        }
      }
    }
  }

  @GwtIncompatible // TODO

  }

  public void testDivide() {
    assertThat(UnsignedLongs.divide(14, 5)).isEqualTo(2);
    assertThat(UnsignedLongs.divide(0, 50)).isEqualTo(0);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffeL, 0xfffffffffffffffdL)).isEqualTo(1);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffdL, 0xfffffffffffffffeL)).isEqualTo(0);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffeL, 65535)).isEqualTo(281479271743488L);

  }

  public void testDivide() {
    assertThat(UnsignedLongs.divide(14, 5)).isEqualTo(2);
    assertThat(UnsignedLongs.divide(0, 50)).isEqualTo(0);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffeL, 0xfffffffffffffffdL)).isEqualTo(1);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffdL, 0xfffffffffffffffeL)).isEqualTo(0);
    assertThat(UnsignedLongs.divide(0xfffffffffffffffeL, 65535)).isEqualTo(281479271743488L);

	switch op {
	case opPlus:
	case opMinus:
	case opDivide:
	case opMultiply:
	case opModulo:
	default:
		return false
	}
	return true
}

// Overflow errors are ignored.
func intArithOp(op string, left, right int64) (int64, error) {
	switch op {
	case opPlus:
		return left + right, nil
	case opMinus:
		return left - right, nil
	case opDivide:
		if right == 0 {
			return 0, errArithDivideByZero

       */
      sqrt0 = sqrtApproxWithDoubles(x.shiftRight(shift)).shiftLeft(shift >> 1);
    }
    BigInteger sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
    if (sqrt0.equals(sqrt1)) {
      return sqrt0;
    }
    do {
      sqrt0 = sqrt1;
      sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
    } while (sqrt1.compareTo(sqrt0) < 0);
    return sqrt0;
  }

  @GwtIncompatible // TODO

        }
        boolean dividesEvenly = (p % q) == 0;
        try {
          assertEquals(p + "/" + q, p, IntMath.divide(p, q, UNNECESSARY) * q);
          assertTrue(p + "/" + q + " not expected to divide evenly", dividesEvenly);
        } catch (ArithmeticException e) {
          assertFalse(p + "/" + q + " expected to divide evenly", dividesEvenly);
        }
      }
    }
  }

  public void testZeroDivIsAlwaysZero() {