Program to clear K-th bit of a number N
Given a number N, the task is to clear the K-th bit of this number N. If K-th bit is 1, then clear it to 0 and if it is 0 then leave it unchanged.
Examples:
Input: N = 5, K = 1 Output: 4 5 is represented as 101 in binary and has its first bit 1, so clearing it will result in 100 i.e. 4. Input: N = 5, K = 2 Output: 5 5 is represented as 101 in binary and has its second bit is already 0, so clearing it will result in 101 i.e. 5.
Approach:
- Since bitwise AND of any bit with a reset bit results in a reset bit, i.e.
Any bit <bitwise AND> Reset bit = Reset bit which means, 0 & 0 = 0 1 & 0 = 0
- So for clearing a bit, performing a bitwise AND of the number with a reset bit is the best idea.
n = n & ~(1 << k) OR n &= ~(1 << k) where k is the bit that is to be cleared
Below is the implementation of the above approach:
C
// C program to clear K-th bit of a number N #include <stdio.h> // Function to clear the kth bit of n int clearBit( int n, int k) { return (n & (~(1 << (k - 1)))); } // Driver code int main() { int n = 5, k = 1; printf ( "%d\n" , clearBit(n, k)); return 0; } |
C++
// C++ program to clear K-th bit of a number N #include <bits/stdc++.h> using namespace std; // Function to clear the kth bit of n int clearBit( int n, int k) { return (n & (~(1 << (k - 1)))); } // Driver code int main() { int n = 5, k = 1; cout<<clearBit(n, k)<<endl; return 0; } // This code is contributed by rutvik_56. |
Python3
# Python3 program to clear # K-th bit of a number N # Function to clear the kth bit of n def clearBit(n, k): return (n & ( ~( 1 << (k - 1 )))) # Driver code n = 5 k = 1 print (clearBit(n, k)) # This code is contributed # by Mohit Kumar |
Java
// Java program to clear K-th bit of a number N class GFG { // Function to clear the kth bit of n static int clearBit( int n, int k) { return (n & (~( 1 << (k - 1 )))); } // Driver code public static void main (String[] args) { int n = 5 , k = 1 ; System.out.println(clearBit(n, k)); } } // This code is contributed by AnkitRai01 |
C#
// C# program to clear K-th bit of a number N using System; class GFG { // Function to clear the kth bit of n static int clearBit( int n, int k) { return (n & (~(1 << (k - 1)))); } // Driver code public static void Main (String[] args) { int n = 5, k = 1; Console.WriteLine(clearBit(n, k)); } } // This code is contributed by PrinciRaj1992 |
Javascript
<script> // JavaScript program to clear K-th bit of a number N // Function to clear the kth bit of n function clearBit(n, k) { return (n & (~(1 << (k - 1)))); } // Driver code var n = 5, k = 1; document.write( clearBit(n, k)); </script> |
Output:
4
Time Complexity: O(1)
Auxiliary Space: O(1)