Practice
Resources
Contests
Online IDE
New
Free Mock
Events New Scaler
Practice
Improve your coding skills with our resources
Contests
Compete in popular contests with top coders
logo
Events
Attend free live masterclass hosted by top tech professionals
New
Scaler
Explore Offerings by SCALER

Bitset

Bitset represents a fixed-size sequence of N bits and stores values either 0 or 1. Zero means value is false or bit is unset and one means value is true or bit is set. Bitset class emulates space efficient array of boolean values, where each element occupies only one bit.

As it emulates array, its index also starts from 0th position. Individual bit from bitset can be accessed using subscript operator.
For instance to access first element of bitset test use test[0].

Bitset class provides constructors to create bitset from integer as well as from strings. The size of the bitset is fixed at compile time.

The main function defined for bitset class are operator [], count, size, set, reset and many more they are explained in below code:

int main(){

// default constructor initializes with all bits 0
bitset<32> bset1;

// bset2 is initialized with bits of 20
bitset<32> bset2(20);

// bset3 is initialized with bits of specified binary string
bitset<32> bset3(string("1100"));

// cout prints exact bits representation of bitset
cout << bset1 << endl; // 00000000000000000000000000000000
cout << bset2 << endl; // 00000000000000000000000000010100
cout << bset3 << endl; // 00000000000000000000000000001100

// declaring set8 with capacity of 8 bits

bitset<8> set8; // 00000000

// setting first bit (or 6th index)
set8[1] = 1; // 00000010
set8[4] = set8[1]; // 00010010
cout << set8 << endl; // 00010010

// count function returns number of set bits in bitset
int numberof1 = set8.count();

// size function returns total number of bits in bitset
// so there difference will give us number of unset(0) bits in bitset
int numberof0 = set8.size() - numberof1;

cout << set8 << " has " << numberof1 << " ones and " << numberof0 << " zeros\n";
// 00010010 has 2 ones and 6 zeros

// test function return 1 if bit is set else returns 0
cout << "bool representation of " << set8 << " : ";
for (int i = 0; i < set8.size(); i++)
cout << set8.test(i) << " ";
cout << endl;
// bool representation of 00010010 : 0 1 0 0 1 0 0 0 

// any function returns true, if atleast 1 bit is set
if (!set8.any())
cout << "set8 has no bit set.\n"; // bset1 has no bit set.

// none function returns true, if none of the bit is set
if (!bset1.none())
cout << "bset1 has some bit set\n";

// set() sets all bits
cout << set8.set() << endl; // 11111111

// set(pos, b)
cout << set8.set(4, 0) << endl; // makes set8[4] = 0
// 11101111

// set(pos)
cout << set8.set(4) << endl; // makes set8[4] = 1 i.e. default is 1
// 11111111

// reset function makes all bits 0
cout << set8.reset(2) << endl; // 11111011
cout << set8.reset() << endl; // 00000000

// flip function flips all bits i.e. 1 <-> 0 and 0 <-> 1
cout << set8.flip(2) << endl; // 00000100
cout << set8.flip() << endl; // 11111011

// Converting decimal number to binary by using bitset
int num = 100;
cout << "\nDecimal number: " << num << " Binary equivalent: " << bitset<8>(num);
// Decimal number: 100 Binary equivalent: 01100100

return 0;
}

For bitset all bitwise operator are overloaded that is they can be applied to bitset directly without any casting or conversion, main overloaded operator are &, |, ==, != and shifting operator <> which makes operation on bitset easy.

int main(){ 
bitset<4> bset1(9); // bset1 contains 1001
bitset<4> bset2(3); // bset2 contains 0011

// comparison operator
cout << (bset1 == bset2) << endl; // false 0
cout << (bset1 != bset2) << endl; // true 1

// bitwise operation and assignment
cout << (bset1 ^= bset2) << endl; // 1010
cout << (bset1 &= bset2) << endl; // 0010
cout << (bset1 |= bset2) << endl; // 0011

// left and right shifting
cout << (bset1 <<= 2) << endl; // 1100
cout << (bset1 >>= 1) << endl; // 0110

// not operator
cout << (~bset2) << endl; // 1100

// bitwise operator
cout << (bset1 & bset2) << endl; // 0010
cout << (bset1 | bset2) << endl; // 0111
cout << (bset1 ^ bset2) << endl; // 0101
}

Try the following example in the editor below.

You are given two bitset b1 and b2, perform the operations defined in the comments in the editor below.

Start solving Bitset on Interview Code Editor
Hints
  • Complete Solution

Discussion


Loading...
Click here to start solving coding interview questions
Free Mock Assessment
Fill up the details for personalised experience.
Phone Number *
OTP will be sent to this number for verification
+1 *
+1
Change Number
Graduation Year *
Graduation Year *
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
*Enter the expected year of graduation if you're student
Current Employer
Company Name
College you graduated from
College/University Name
Job Title
Job Title
Engineering Leadership
Software Development Engineer (Backend)
Software Development Engineer (Frontend)
Software Development Engineer (Full Stack)
Data Scientist
Android Engineer
iOS Engineer
Devops Engineer
Support Engineer
Research Engineer
Engineering Intern
QA Engineer
Co-founder
SDET
Product Manager
Product Designer
Backend Architect
Program Manager
Release Engineer
Security Leadership
Database Administrator
Data Analyst
Data Engineer
Non Coder
Other
Please verify your phone number
Edit
Resend OTP
By clicking on Start Test, I agree to be contacted by Scaler in the future.
Already have an account? Log in
Free Mock Assessment
Instructions from Interviewbit
Start Test