Package net.cscott.jutil

Class Util

java.lang.Object
net.cscott.jutil.Util
public abstract class Util extends Object
Miscellaneous static utility functions.
Author:
C. Scott Ananian <cananian@alumni.princeton.edu>

  • Constructor Details

    • Util

      public Util()

  • Method Details

    • repeatString

      @Deprecated(since="2.0") public static final String repeatString(String s, int n)
      Deprecated.
      Use String.repeat(int).
      Repeat a given string a certain number of times.
      Returns:
      a string consisting of s repeated n times.

    • ffs

      public static final int ffs(int v)
      Find first set (least significant bit).
      Returns:
      the first bit set in the argument. ffs(0)==0 and ffs(1)==1.

    • ffs

      public static final int ffs(long v)
      Find first set (least significant bit).
      Returns:
      the first bit set in the argument. ffs(0)==0 and ffs(1)==1.

    • fls

      public static final int fls(int v)
      Find last set (most significant bit).
      Returns:
      the last bit set in the argument. fls(0)==0 and fls(1)==1.

    • fls

      public static final int fls(long v)
      Find last set (most significant bit).
      Returns:
      the last bit set in the argument. fls(0)==0 and fls(1)==1.

    • log2c

      public static final int log2c(int v)
      Returns ceil(log2(n))

    • zerocount

      @Deprecated(since="2.0") public static final int zerocount(int v)
      Deprecated.
      Use Integer.bitCount(~v).
      Return the number of zeros in the binary representation of the value of the argument.

    • zerocount

      @Deprecated(since="2.0") public static final int zerocount(long v)
      Deprecated.
      Use Long.bitCount(~v).
      Return the number of zeros in the binary representation of the value of the argument.

    • popcount

      @Deprecated(since="2.0") public static final int popcount(int v)
      Deprecated.
      Use Integer.bitCount(int).
      Return the number of ones in the binary representation of the value of the argument.

    • popcount

      @Deprecated(since="2.0") public static final int popcount(long v)
      Deprecated.
      Use Long.bitCount(long).
      Return the number of ones in the binary representation of the value of the argument.

    • gcd

      public static final long gcd(long u, long v)
      Returns the greatest common divisor of a pair of numbers.

    • gcd

      public static final int gcd(int u, int v)
      Returns the greatest common divisor of a pair of numbers.