Set the K-th bit of a given number

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.

Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

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++

 // C++ implementation to set the kth bit // of the given number #include    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

 // 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.

Python3

 # 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#

 // 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



Output:

Kth bit set number = 14

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