Package g2101_2200.s2166_design_bitset

Class Bitset

  • All Implemented Interfaces:
    
public final class Bitset

    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 <code>i<sup>th</sup></code> index should coincide with the value at the <code>i<sup>th</sup></code> 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:

    • <code>1 <= size <= 10<sup>5</sup></code>

    • 0 &lt;= idx &lt;= size - 1

    • At most <code>10<sup>5</sup></code> 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.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Bitset(Integer sz)

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description