All about Bit Manipulation - GeeksforGeeks

24 Apr, 2022
Bit Manipulation is a technique used in a variety of problems to get the solution in an optimized way. This technique is very effective from a Competitive Programming point of view. It is all about Bitwise Operators which directly works upon binary numbers or bits of numbers that help the implementation fast. Below are the Bitwise Operators that are used:
Bitwise AND (&)
Bitwise OR (|)
Bitwise XOR (^)
Bitwise NOT (!)
Learn more about Bitwise Operators in this article.
Below are some common bit operations that are frequently used in programming:
Below is the table to illustrate the result when the operation is performed using Bitwise Operators. Here 0s or 1s mean a sequence of 0 or 1 respectively.
This method is used to find the bit at a particular position(say i) of the given number N. The idea is to find the Bitwise AND of the given number and 2i that can be represented as (1 << i). If the value return is 1 then the bit at the ith position is set. Otherwise, it is unset.
Below is the pseudo-code for the same:
C++
Java
Python3
C#
Javascript
// Function to get the bit at the// ith positionboolean getBit(int num, int i){    // Return true if the bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);}
// Function to get the bit at the// ith positionstatic boolean getBit(int num, int i){    // Return true if the bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // This code is contributed by rishavmahato348.
# Function to get the bit at the# ith positiondef getBit(num, i):       # Return true if the bit is    # set. Otherwise return false    return ((num & (1 << i)) != 0)     # This code is contributed by shivani
// Function to get the bit at the// ith positionstatic bool getBit(int num, int i){    // Return true if the bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // This code is contributed by subhammahato348.
<script> // Function to get the bit at the// ith positionfunction getBit(num, i){         // Return true if the bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // This code is contributed by Ankita saini </script>
This method is used to set the bit at a particular position(say i) of the given number N. The idea is to update the value of the given number N to the Bitwise OR of the given number N and 2i that can be represented as (1 << i). If the value return is 1 then the bit at the ith position is set. Otherwise, it is unset.
Below is the pseudo-code for the same:
C++
Java
Python3
C#
Javascript
// Function to set the ith bit of the// given number numint setBit(int num, int i){    // Sets the ith bit and return    // the updated value    return num | (1 << i);}
// Function to set the ith bit of the// given number numstatic int setBit(int num, int i){    // Sets the ith bit and return    // the updated value    return num | (1 << i);} // This code is contributed by subhammahato348
# Function to set the ith bit of the# given number numdef setBit(num, i):         # Sets the ith bit and return    # the updated value    return num | (1 << i) # This code is contributed by kirti
// Function to set the ith bit of the// given number numstatic int setBit(int num, int i){    // Sets the ith bit and return    // the updated value    return num | (1 << i);}
// Function to set the ith bit of the// given number numfunction setBit(num, i){    // Sets the ith bit and return    // the updated value    return num | (1 << i);}
This method is used to clear the bit at a particular position(say i) of the given number N. The idea is to update the value of the given number N to the Bitwise AND of the given number N and the compliment of 2i that can be represented as ~(1 << i). If the value return is 1 then the bit at the ith position is set. Otherwise, it is unset.
Below is the pseudo-code for the same:
C++
Java
Python3
C#
Javascript
// Function to clear the ith bit of// the given number Nint clearBit(int num, int i){     // Create the mask for the ith    // bit unset    int mask = ~(1 << i);     // Return the update value    return num & mask;}
// Function to clear the ith bit of// the given number Nstatic int clearBit(int num, int i){     // Create the mask for the ith    // bit unset    int mask = ~(1 << i);     // Return the update value    return num & mask;} // This code is contributed by subham348
# Function to clear the ith bit of# the given number N def clearBit(num, i):     # Create the mask for the ith    # bit unset    mask = ~(1 << i)     # Return the update value    return num & mask # This code is contributed by subhammahato348
// Function to clear the ith bit of// the given number Nstatic int clearBit(int num, int i){     // Create the mask for the ith    // bit unset    int mask = ~(1 << i);     // Return the update value    return num & mask;} // This code is contributed by Ankita Saini
// Function to clear the ith bit of// the given number Nfunction clearBit(num, i){     // Create the mask for the ith    // bit unset    let mask = ~(1 << i);     // Return the update value    return num & mask;} // This code is contributed by souravmahato348.
Below is the program that implements the above functionalities:
C++
Java
Python
C#
Javascript
// C++ program to implement all the// above functionalities #include "bits/stdc++.h"using namespace std; // Function to get the bit at the// ith positionbool getBit(int num, int i){    // Return true if the ith bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // Function to set the ith bit of the// given number numint setBit(int num, int i){    // Sets the ith bit and return    // the updated value    return num | (1 << i);} // Function to clear the ith bit of// the given number Nint clearBit(int num, int i){     // Create the mask for the ith    // bit unset    int mask = ~(1 << i);     // Return the update value    return num & mask;} // Driver Codeint main(){    // Given number N    int N = 70;     cout << "The bit at the 3rd position from LSB is: "         << (getBit(N, 3) ? '1' : '0')         << endl;     cout << "The value of the given number "         << "after setting the bit at "         << "LSB is: "         << setBit(N, 0) << endl;     cout << "The value of the given number "         << "after clearing the bit at "         << "LSB is: "         << clearBit(N, 0) << endl;     return 0;}
// Java program to implement all the// above functionalitiesimport java.io.*; class GFG{ // Function to get the bit at the// ith positionstatic boolean getBit(int num, int i){         // Return true if the ith bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // Function to set the ith bit of the// given number numstatic int setBit(int num, int i){         // Sets the ith bit and return    // the updated value    return num | (1 << i);} // Function to clear the ith bit of// the given number Nstatic int clearBit(int num, int i){         // Create the mask for the ith    // bit unset    int mask = ~(1 << i);     // Return the update value    return num & mask;} // Driver Codepublic static void main(String[] args){         // Given number N    int N = 70;     System.out.println("The bit at the 3rd position from LSB is: " +                       (getBit(N, 3) ? '1' : '0'));     System.out.println("The value of the given number " +                       "after setting the bit at " +                       "LSB is: " + setBit(N, 0));     System.out.println("The value of the given number " +                       "after clearing the bit at " +                       "LSB is: " + clearBit(N, 0));}} // This code is contributed by souravmahato348
# Python program to implement all the# above functionalities# Function to get the bit at the# ith positiondef getBit( num,  i):     # Return true if the ith bit is    # set. Otherwise return false    return ((num & (1 << i)) != 0) # Function to set the ith bit of the# given number numdef setBit( num,  i):     # Sets the ith bit and return    # the updated value    return num | (1 << i) # Function to clear the ith bit of# the given number Ndef clearBit( num,  i):         # Create the mask for the ith    # bit unset    mask = ~(1 << i)         # Return the update value    return num & mask # Driver Code# Given number NN = 70print"The bit at the 3rd position from LSB is: " , 1 if (getBit(N, 3)) else '0' print"The value of the given number" , "after setting the bit at","LSB is: " , setBit(N, 0) print"The value of the given number" , "after clearing the bit at","LSB is: " , clearBit(N, 0) # This code is contributed by shivanisinghss2110
// C# program to implement all the// above functionalitiesusing System; class GFG {     // Function to get the bit at the    // ith position    static bool getBit(int num, int i)    {         // Return true if the ith bit is        // set. Otherwise return false        return ((num & (1 << i)) != 0);    }     // Function to set the ith bit of the    // given number num    static int setBit(int num, int i)    {         // Sets the ith bit and return        // the updated value        return num | (1 << i);    }     // Function to clear the ith bit of    // the given number N    static int clearBit(int num, int i)    {         // Create the mask for the ith        // bit unset        int mask = ~(1 << i);         // Return the update value        return num & mask;    }     // Driver Code    public static void Main()    {         // Given number N        int N = 70;         Console.WriteLine("The bit at the 3rd position form LSB is: "                          + (getBit(N, 3) ? '1' : '0'));         Console.WriteLine("The value of the given number "                          + "after setting the bit at "                          + "LSB is: " + setBit(N, 0));         Console.WriteLine("The value of the given number "                          + "after clearing the bit at "                          + "LSB is: " + clearBit(N, 0));    }} // This code is contributed by rishavmahato348.
<script> // Javascript program to implement all// the above functionalities // Function to get the bit at the// ith positionfunction getBit(num, i){         // Return true if the ith bit is    // set. Otherwise return false    return ((num & (1 << i)) != 0);} // Function to set the ith bit of the// given number numfunction setBit(num, i){         // Sets the ith bit and return    // the updated value    return num | (1 << i);} // Function to clear the ith bit of// the given number Nfunction clearBit(num, i){     // Create the mask for the ith    // bit unset    let mask = ~(1 << i);     // Return the update value    return num & mask;} // Driver code // Given number Nlet N = 70; document.write("The bit at the 3rd position from LSB is: " +              (getBit(N, 3) ? '1' : '0') + "</br>"); document.write("The value of the given number " +               "after setting the bit at " +               "LSB is: " + setBit(N, 0) + "</br>"); document.write("The value of the given number " +               "after clearing the bit at " +               "LSB is: " + clearBit(N, 0) + "</br>");                // This code is contributed by divyeshrabadiya07 </script>
The bit at the 3rd position is: 0
The value of the given number  after setting the bit at  MSB is: 71
The value of the given number  after clearing the bit at  MSB is: 70
 
rishavmahato348
subhammahato348
subham348
ankita_saini
shivanisinghss2110
Kirti_Mangal
divyeshrabadiya07
souravmahato348
Bit Algorithms
Bitwise-AND
Bitwise-OR
Bitwise-XOR
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