tmp += BigIntegerMath.factorial(factorials[j]).intValue();
    }
    return tmp;
  }

  @Benchmark
  int binomial(int reps) {
    int tmp = 0;
    for (int i = 0; i < reps; i++) {
      int j = i & 0xffff;
      tmp += BigIntegerMath.binomial(factorials[j], binomials[j]).intValue();
    }
    return tmp;
  }

          longsToMul[i][j] = randomBigInteger(Long.SIZE - 2).longValue();
        }
      } while (!Impl.GUAVA.noMulOverflow(longsToMul[i][0], longsToMul[i][1]));

      int k = binomials[i][1] = RANDOM_SOURCE.nextInt(MathBenchmarking.biggestBinomials.length);
      binomials[i][0] = RANDOM_SOURCE.nextInt(MathBenchmarking.biggestBinomials[k] - k) + k;
    }
  }

  @Benchmark
  long factorialDouble(int reps) {
    long tmp = 0;

          longsToMul[i][j] = randomBigInteger(Long.SIZE - 2).longValue();
        }
      } while (!Impl.GUAVA.noMulOverflow(longsToMul[i][0], longsToMul[i][1]));

      int k = binomials[i][1] = RANDOM_SOURCE.nextInt(MathBenchmarking.biggestBinomials.length);
      binomials[i][0] = RANDOM_SOURCE.nextInt(MathBenchmarking.biggestBinomials[k] - k) + k;
    }
  }

  @Benchmark
  long factorialDouble(int reps) {
    long tmp = 0;

  static final Random RANDOM_SOURCE = new Random(314159265358979L);
  static final int MAX_EXPONENT = 100;

  /*
   * Duplicated from LongMath.
   * binomial(biggestBinomials[k], k) fits in a long, but not
   * binomial(biggestBinomials[k] + 1, k).
   */
  static final int[] biggestBinomials = {
    Integer.MAX_VALUE,
    Integer.MAX_VALUE,
    Integer.MAX_VALUE,
    3810779,
    121977,

        assertEquals(expected, BigIntegerMath.binomial(n, k));
      }
    }
  }

  public void testBinomialOutside() {
    for (int i = 0; i <= 50; i++) {
      int n = i;
      assertThrows(IllegalArgumentException.class, () -> BigIntegerMath.binomial(n, -1));
      assertThrows(IllegalArgumentException.class, () -> BigIntegerMath.binomial(n, n + 1));
    }
  }

  @J2ktIncompatible

  /**
   * Returns {@code n} choose {@code k}, also known as the binomial coefficient of {@code n} and
   * {@code k}, that is, {@code n! / (k! (n - k)!)}.
   *
   * <p><b>Warning:</b> the result can take as much as <i>O(k log n)</i> space.
   *
   * @throws IllegalArgumentException if {@code n < 0}, {@code k < 0}, or {@code k > n}
   */
  public static BigInteger binomial(int n, int k) {
    checkNonNegative("n", n);

  };

  /**
   * Returns {@code n} choose {@code k}, also known as the binomial coefficient of {@code n} and
   * {@code k}, or {@link Integer#MAX_VALUE} if the result does not fit in an {@code int}.
   *
   * @throws IllegalArgumentException if {@code n < 0}, {@code k < 0} or {@code k > n}
   */
  public static int binomial(int n, int k) {
    checkNonNegative("n", n);
    checkNonNegative("k", k);

          permutations = IntMath.saturatedMultiply(permutations, IntMath.binomial(n, r));
          r = 0;
          if (permutations == Integer.MAX_VALUE) {
            return Integer.MAX_VALUE;
          }
        }
        n++;
        r++;
      }
      return IntMath.saturatedMultiply(permutations, IntMath.binomial(n, r));
    }

    @Override
    public int size() {
      return size;

                return size;
              }
            };
          }
        };
      }

      @Override
      public int size() {
        return IntMath.binomial(index.size(), size);
      }

      @Override
      public String toString() {
        return "Sets.combinations(" + index.keySet() + ", " + size + ")";
      }
    };
  }

                return size;
              }
            };
          }
        };
      }

      @Override
      public int size() {
        return IntMath.binomial(index.size(), size);
      }

      @Override
      public String toString() {
        return "Sets.combinations(" + index.keySet() + ", " + size + ")";
      }
    };
  }