Given a number n and a value k. From the right, set the kth bit in the binary representation of n. The position of LSB(or last bit) is 0, second last bit is 1 and so on. Also, 0 <= k < x, where x is the number of bits in the binary representation of n.
Examples:
Input : n = 10, k = 2 Output : 14 (10)10 = (1010)2 Now, set the 2nd bit from right. (14)10 = (1110)2 2nd bit has been set. Input : n = 15, k = 3 Output : 15 3rd bit of 15 is already set.
To set any bit we use bitwise OR | operator. As we already know bitwise OR | operator evaluates each bit of the result to 1 if any of the operand’s corresponding bit is set (1). In-order to set kth bit of a number we need to shift 1 k times to its left and then perform bitwise OR operation with the number and result of left shift performed just before.
In general, (1 << k) | n.
// C++ implementation to set the kth bit // of the given number #include <bits/stdc++.h> using namespace std;
// function to set the kth bit int setKthBit( int n, int k)
{ // kth bit of n is being set by this operation
return ((1 << k) | n);
} // Driver program to test above int main()
{ int n = 10, k = 2;
cout << "Kth bit set number = "
<< setKthBit(n, k);
return 0;
} |
// Java implementation to set the kth bit // of the given number class GFG {
// function to set the kth bit static int setKthBit( int n, int k)
{ // kth bit of n is being set by this operation
return (( 1 << k) | n);
} // Driver code public static void main(String arg[])
{ int n = 10 , k = 2 ;
System.out.print( "Kth bit set number = " +
setKthBit(n, k));
} } // This code is contributed by Anant Agarwal. |
# Python implementation # to set the kth bit # of the given number # function to set # the kth bit def setKthBit(n,k):
# kth bit of n is being
# set by this operation
return (( 1 << k) | n)
# Driver code n = 10
k = 2
print ( "Kth bit set number = " ,
setKthBit(n, k))
# This code is contributed # by Anant Agarwal. |
// C# implementation to set the // kth bit of the given number using System;
class GFG {
// function to set the kth bit static int setKthBit( int n, int k)
{ // kth bit of n is being set
// by this operation
return ((1 << k) | n);
} // Driver code public static void Main()
{ int n = 10, k = 2;
Console.Write( "Kth bit set number = "
+ setKthBit(n, k));
} } // This code is contributed by // Smitha Dinesh Semwal. |
<?php // PHP implementation to // set the kth bit of // the given number // function to set // the kth bit function setKthBit( $n , $k )
{ // kth bit of n is being
// set by this operation
return ((1 << $k ) | $n );
} // Driver Code $n = 10; $k = 2;
echo "Kth bit set number = " ,
setKthBit( $n , $k );
// This code is contributed by m_kit ?> |
<script> // Javascript implementation to set the
// kth bit of the given number
// function to set the kth bit
function setKthBit(n, k)
{
// kth bit of n is being set
// by this operation
return ((1 << k) | n);
}
let n = 10, k = 2;
document.write( "Kth bit set number = " + setKthBit(n, k));
// This code is contributed by rameshtravel07.
</script> |
Output:
Kth bit set number = 14
Time Complexity: O(1)
Auxiliary Space: O(1)