Package g2101_2200.s2166_design_bitset

Class Bitset

java.lang.Object
g2101_2200.s2166_design_bitset.Bitset
public class Bitset extends java.lang.Object
2166 - Design Bitset.

Medium

A Bitset is a data structure that compactly stores bits.

Implement the Bitset class:

  • Bitset(int size) Initializes the Bitset with size bits, all of which are 0.
  • void fix(int idx) Updates the value of the bit at the index idx to 1. If the value was already 1, no change occurs.
  • void unfix(int idx) Updates the value of the bit at the index idx to 0. If the value was already 0, no change occurs.
  • void flip() Flips the values of each bit in the Bitset. In other words, all bits with value 0 will now have value 1 and vice versa.
  • boolean all() Checks if the value of each bit in the Bitset is 1. Returns true if it satisfies the condition, false otherwise.
  • boolean one() Checks if there is at least one bit in the Bitset with value 1. Returns true if it satisfies the condition, false otherwise.
  • int count() Returns the total number of bits in the Bitset which have value 1.
  • String toString() Returns the current composition of the Bitset. Note that in the resultant string, the character at the ith index should coincide with the value at the ith bit of the Bitset.

Example 1:

Input

[“Bitset”, “fix”, “fix”, “flip”, “all”, “unfix”, “flip”, “one”, “unfix”, “count”, “toString”]

[[5], [3], [1], [], [], [0], [], [], [0], [], []]

Output: [null, null, null, null, false, null, null, true, null, 2, “01010”]

Explanation:

 Bitset bs = new Bitset(5); // bitset = "00000".
 bs.fix(3); // the value at idx = 3 is updated to 1, so bitset = "00010".
 bs.fix(1); // the value at idx = 1 is updated to 1, so bitset = "01010".
 bs.flip(); // the value of each bit is flipped, so bitset = "10101".
 bs.all(); // return False, as not all values of the bitset are 1.
 bs.unfix(0); // the value at idx = 0 is updated to 0, so bitset = "00101".
 bs.flip(); // the value of each bit is flipped, so bitset = "11010".
 bs.one(); // return True, as there is at least 1 index with value 1.
 bs.unfix(0); // the value at idx = 0 is updated to 0, so bitset = "01010".
 bs.count(); // return 2, as there are 2 bits with value 1.
 bs.toString(); // return "01010", which is the composition of bitset.

Constraints:

  • 1 <= size <= 105
  • 0 <= idx <= size - 1
  • At most 105 calls will be made in total to fix, unfix, flip, all, one, count, and toString.
  • At least one call will be made to all, one, count, or toString.
  • At most 5 calls will be made to toString.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Bitset(int size)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    all()
     
    int
    count()
     
    void
    fix(int idx)
     
    void
    flip()
     
    boolean
    one()
     
    java.lang.String
    toString()
     
    void
    unfix(int idx)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Bitset

      public Bitset(int size)

  • Method Details

    • fix

      public void fix(int idx)

    • unfix

      public void unfix(int idx)

    • flip

      public void flip()

    • all

      public boolean all()

    • one

      public boolean one()

    • count

      public int count()

    • toString

      public java.lang.String toString()
      Overrides:
      toString in class java.lang.Object