# Find, Set, Clear, Toggle and Modify bits in C

Given a positive integer **N**, the task is to perform the following sequence of operations on the binary representation of **N** in C.

- Finding a bit: Find the
**K**bit in binary representation of^{th}**N**. - Setting a bit: If
**K**bit is^{th}**0**, then set it to**1**. Otherwise, leave it unchanged. - Clearing a bit: If K
^{th}bit is**1**, then clear it to**0**. Otherwise, leave it unchanged. - Toggling a bit: If
**K**bit is^{th}**1**, then change it to**0**and vice-versa. - Modifying a bit: Replace the
**K**bit with a given bit.^{th}

**Examples:**

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Input:N = 5, K = 1, P = 0Output:

K(= 1)^{th}bit of 5 is 1.

Setting the K(= 1)^{th}bit modifies N to 5

Clearing the K(= 1)^{th}bit modifies N to 4.

Toggling the K(= 1)^{th}bit modifies N to 4.

Replacing the K(= 1)^{th}bit with P(= 0) modifies N to 4

Input: N = 10, K = 2, P = 1Output:

K^{th}(= 2) bit of 5 is 1.

Setting the K(= 2)^{th}bit modifies N to 10.

Clearing the K(= 2)^{th}bit modifies N to 8.

Toggling the K(= 2)^{th}bit modifies N to 8.

Replacing the K(= 2)^{th}bit with P(= 1) modifies N to 10.

**Approach:** Follow the steps below to find, set, clear, toggle and modify the K^{th} bit in the binary representation of **N**.

**Finding a bit:**

(N >> K) & 1

**Setting a bit:**

N = N | (1 << K)

**Clearing a bit:**

N = N & ~(1 << K)

**Toggle a bit:**

N = N ^ (1 << K)

**Modify a bit:**

N = N | (P << K)

Below is the implementation of the above approach:

## C

`// C program to implement` `// the above approach` ` ` `#include <stdio.h>` ` ` `// Function to set the kth bit of n` `int` `setBit(` `int` `n, ` `int` `k)` `{` ` ` `return` `(n | (1 << (k - 1)));` `}` ` ` `// Function to clear the kth bit of n` `int` `clearBit(` `int` `n, ` `int` `k)` `{` ` ` `return` `(n & (~(1 << (k - 1))));` `}` ` ` `// Function to toggle the kth bit of n` `int` `toggleBit(` `int` `n, ` `int` `k)` `{` ` ` `return` `(n ^ (1 << (k - 1)));` `}` ` ` `// Function to modify k-th bit with p` `int` `modifyBit(` `int` `n, ` `int` `k, ` `int` `p)` `{` ` ` `return` `(n | (p << k));` `}` ` ` `// Function to find the kth bit of n` `int` `findBit(` `int` `n, ` `int` `k)` `{` ` ` `return` `((n >> k) & 1);` `}` ` ` `// Utility function to perform` `// the specified Bit Operations` `void` `bitOperations(` `int` `n, ` `int` `k,` ` ` `int` `p)` `{` ` ` ` ` `printf` `(` `"K(= %d)-th bit of %d is %d\n"` `,` ` ` `k, n, findBit(n, k));` ` ` ` ` `printf` `(` `"Setting K(= %d)th bit modifies N to %d\n"` `,` ` ` `k, setBit(n, k));` ` ` ` ` `printf` `(` `"Clearing K(= %d)th bit modifies N to %d\n"` `,` ` ` `k, clearBit(n, k));` ` ` ` ` `printf` `(` `"Toggling K(= %d)th bit modifies N to %d\n"` `,` ` ` `k, toggleBit(n, k));` ` ` ` ` `printf` `(` `"Replacing the K(= %d)<sup>th</sup> bit"` `, k);` ` ` `printf` `(` `" with P(= %d) modifies N to 10\n"` `,` ` ` `modifyBit(n, k, p));` `}` ` ` `// Driver Code` `int` `main()` `{` ` ` `int` `n = 5, k = 1, p = 1;` ` ` `bitOperations(n, k, p);` ` ` ` ` `return` `0;` `}` |

**Output:**

K(= 1)-th bit of 5 is 0 Setting K(= 1)th bit modifies N to 5 Clearing K(= 1)th bit modifies N to 4 Toggling K(= 1)th bit modifies N to 4 Replacing the K(= 1)^{th}bit with P(= 7) modifies N to 10

**Time Complexity:** O(log(N))**Auxiliary Space:** O(1)