Revert "#7430 implemented multiFactorial"

This reverts commit b6cd5c7.

Author: YujingZHG

guava/src/com/google/common/math/BigIntegerMath.java

@@ -521,33 +521,5 @@ static boolean fitsInLong(BigInteger x) {
     return x.bitLength() <= Long.SIZE - 1;
   }
 
-  /**
-   * Returns multifactorial of n with step size BigInteger k.
-   * This is used for large values of n.
-   *
-   * @param n the number to compute the multifactorial of. Must be non-negative.
-   * @param k the step size. Must be positive.
-   * @return the multifactorial of n with step size k. If none-zero n is less than k then return n, else return one.
-   * @throws IllegalArgumentException if n is negative or if k is less than 1.
-   */
-  public static BigInteger multiFactorial(int n, int k) {
-    if (n < 0) {
-      throw new IllegalArgumentException("n cannot be negative!");
-    }
-    if (k < 1) {
-      throw new IllegalArgumentException("k must be positive!");
-    }
-
-    if (n <= k) {
-      return n == 0 ? BigInteger.ONE : BigInteger.valueOf(n);
-    }
-
-    BigInteger result = BigInteger.valueOf(n);
-    for (int i = n - k; i > 1; i -= k) {
-      result = result.multiply(BigInteger.valueOf(i));
-    }
-    return result;
-  }
-
   private BigIntegerMath() {}
 }

guava/src/com/google/common/math/IntMath.java

@@ -722,32 +722,5 @@ public static boolean isPrime(int n) {
     return LongMath.isPrime(n);
   }
 
-  /**
-   * Returns multifactorial of Int n with step size k.
-   *
-   * @param n the number to compute. Must be non-negative.
-   * @param k the step size for the multifactorial. Must be positive.
-   * @return the multifactorial of n with step size k. If none-zero n is less than k then return n, else return 1.
-   * @throws IllegalArgumentException if n is negative or if k is less than 1.
-   */
-  public static int multiFactorial(int n, int k) {
-    if (n < 0) {
-      throw new IllegalArgumentException("n cannot be negative!");
-    }
-    if (k < 1) {
-      throw new IllegalArgumentException("k must be positive!");
-    }
-    if (n <= k) {
-      return n == 0 ? 1 : n;
-    }
-
-    int result = n;
-    for (int i = n - k; i > 1; i -= k) {
-      result *= i;
-    }
-    return result;
-  }
-
   private IntMath() {}
-
 }

guava/src/com/google/common/math/LongMath.java

@@ -1346,31 +1346,5 @@ public static double roundToDouble(long x, RoundingMode mode) {
     throw new AssertionError("impossible");
   }
 
-  /**
-   * Returns multifactorial of int n with step size k.
-   *
-   * @param n the number to compute. Must be non-negative.
-   * @param k the step size must be positive.
-   * @return the long type multifactorial of n with step size k. If none-zero n is less than k then return (long) n, else return 1L.
-   * @throws IllegalArgumentException if n is negative or if k is less than 1.
-   */
-  public static long multiFactorial(int n, int k) {
-    if (n < 0) {
-      throw new IllegalArgumentException("n cannot be negative!");
-    }
-    if (k < 1) {
-      throw new IllegalArgumentException("k must be positive!");
-    }
-    if (n <= k) {
-      return n == 0 ? 1L : (long)n;
-    }
-
-    long result = n;
-    for (long i = n - k; i > 1; i -= k) {
-      result *= i;
-    }
-    return result;
-  }
-
   private LongMath() {}
 }