C++ Bitset Flip Function

In the C++ programming language, the std::bitset class is an efficient method to work with sequences of bits of fixed size. It provides several functions to manipulate the bits. The flip function is an important function that flips the bits in either the whole bitset or at a particular index from 0 to 1 and 1 to 0.

The C++ bitset flip function is commonly used to flip all the bit values, which converts zeros to ones and ones to zeros. If a parameter 'position' is passed, it flips the bit at the specified position only. It is an important feature in many algorithms or approaches where toggling, complementing, or switching the states of binary values is required. When we perform the operation using the bitset flip function, 0 becomes 1 and 1 becomes 0.

Syntax

It has the following syntax:

bs.flip ();  

bs.flip (int pos);

In this syntax,

• ✅ pos: It takes one parameter 'pos', but it is not mandatory.

Return value

• ✅ It returns a new binary representation of a number.

Working of the bitwise flip function in C++

In the C++ programming language, the flip function works internally by using the bitwise NOT (~) operation to flip all the bits. If we want to flip a specific bit at position pos, we apply XOR with a mask.

• ✅ Flip all bits: bitset = ~bitset;
• ✅ Flip one bit: bitset ^= (1 << pos);

This efficient use of bitwise operations creates an efficient constant-time (O(1)) function flip.

Simple C++ bitwise flip function Example

Let us take an example to illustrate the bitwise flip function in C++.

Example

#include <iostream>  

#include <bitset>  

using namespace std;   //using standard namespace

int main()    //main function

{  

bitset<4> b(string("0101"));  

cout<<b.flip();  

return 0;  

}

Output:

Explanation:

In this example, we have taken a bitset of 4 bits (0101). After that, we use the flip function that flips the bits, which is displayed in the output.

C++ Example to flip the bits using the flip Function

Let us take an example to illustrate how to flip the bits in the bitset using the flip function in C++.

Example

#include <iostream>  

#include <bitset>  

using namespace std;    //using standard namespace

int main()    //main function

{  

bitset<4> b(string("0101"));  

bitset<6> b1(string("011010"));  

cout<<b.flip(3) << '\n';  

cout<< b1.flip(4);  

return 0;  

}

Output:

1101

001010

Explanation:

In this example, we have taken two bitsets b and b1 that are initialized with binary values "0101" and "011010". After that, we have utilized the flip function to toggle the bit at the specified position, which flips the bits 0 to 1 or 1 to 0. Therefore, the b.flip(3) flips the 3rd bit of b, and b1.flip(4) flips the 4th bit of b1.

C++ Example to flip a specific bit using the flip function

Let's consider an example to illustrate how to flip a specific bit using the flip function in C++.

Example

#include <bitset>

#include <iostream>

using namespace std;   //using standard namespace

int main() {   //main function

    bitset<8> b2(12);    // Binary: 00001100

    cout << "Original: " << b2 << endl;

    b2.flip(2); // Flip the bit at index 2 (from right, 0-based)

    cout << "After flip at pos 2: " << b2 << endl;

    b2.flip(5); // Flip the bit at index 5

    cout << "After flip at pos 5: " << b2 << endl;

    return 0;

}

Output:

Original: 00001100

After flip at pos 2: 00001000

After flip at pos 5: 00101000

Explanation:

In this example, we have taken a bitset of 8 bits that contains a bitset 00001100. After that, we have utilized the bitset flip function to flip the specific bit. First, it flips the bit of position 2, and then it flips the bit of position 5. Each flip changes the specific bits' value from 0 to 1 and from 1 to 0. Finally, it displayed the updated bitset in the console.

C++ Example to flip all bits and specific bits in a C++ bitset using the flip function

Let us consider an example to flip all bits and specific bits in the bitset using the flip function in C++.

Example

#include <bitset>

#include <iostream>

using namespace std;    //using standard namespace

int main() {    //main function

    bitset<8> b3(170);     // 170 -> 10101010

    cout << "Original: " << b3 << endl;

    b3.flip();    // Flip all bits

    cout << "After full flip: " << b3 << endl;

    b3.flip(0); // Flip the least significant bit

    cout << "After flipping LSB: " << b3 << endl;

    cout << "Number of set bits: " << b3.count() << endl;

    cout << "Number of unset bits: " << b3.size() - b3.count() << endl;

    return 0;

}

Output:

Original: 10101010

After full flip: 01010101

After flipping LSB: 01010100

Number of set bits: 3

Number of unset bits: 5

Explanation:

In this example, we have taken a bitset of 8 bits that is initialized with the value of 170, whose binary pattern is 10101010. After that, we have utilized the flip function that flips all the given bits, which turns 10101010 into 01010101. Next, we get the Least Significant Bit using the flip(0) function. Finally, it calculates and prints the number of set and unset bits in the modified bits.

Complexity Analysis for the Bitset flip function

The bitset flip function takes some time and space to perform the flip operations in the bitset. Therefore, the complexity analysis for the flip function in C++ is as follows:

• ✅ Time Complexity: It takes only O(1) time complexity for flipping either all bits or a single bit.
• ✅ Space Complexity: It takes only O(1) space because it doesn't require any additional space.

Features of the Bitset flip function in C++

There are several features of the bitset flip function in C++. Some of them are as follows:

• ✅ The C++ bitset flip function is commonly utilized to flip the bits in the bitset, which changes the bits 0 to 1 and 1 to 0.
• ✅ We can directly modify the bitset using the flip function, and it can also be used in the chain expression because it returns a reference to the modified bitset.
• ✅ We can flip all bits at once, and can also flip the specific bit at a given position.
• ✅ It takes only constant time O(1) complexity, which makes it very useful for bit manipulation in C++.
• ✅ It can be utilized in several applications, such as bitwise operations, data encoding, and flag toggling.

Conclusion

In conclusion, the C++ bitset::flip function is an efficient and straightforward method for flipping bits in a fixed-size bitset. The flip function abstracts the low-level bitwise operations and retains their performance. If we want to flip all bits, or want to change only a bit, the flip function is a very useful method to flip the bits. When the flip function is combined with the set, reset, and count functions, we can create complex processing logic.

C++ Bitset flip Function FAQs

1) What does the bitset::flip function do in C++?

In the C++ programming language, the flip function changes each bit in a bitset, switching '0' to '1', and '1' to '0'. We can either flip all the bits simultaneously or flip just one bit at a given position.

2) What is the difference between the flip and flip(pos) in C++?

The main difference between the flip and flip(pos) functions is that the flip function throws every bit in the bitset. In contrast, the flip(pos) changes the bit at the position mentioned only. As a result, it fits both usages that require flipping all bits at once and one single bit at the same time.

3) What happens when we provide an invalid index in flip(pos) in C++?

If the index is greater than the bitset size, flip(pos) will throw a std::outofrange exception. It ensures that access is done safely and undefined behavior is avoided.

4) Is the flip function efficient in terms of time complexity in C++?

In C++, the flip function is very efficient. It simply happens to utilize fast bitwise operations. Both versions are constant-time O(1) operations.

5) When should we use the bitset::flip function in a practical application in C++?

In C++, we should use the flip function to toggle switch values, flip masks, for error correction, as well as basic encryption. It is also used in simulations or games that toggle the state.