# Toggle all the bits of a number except k-th bit.

Given a positive (or unsigned) integer n, write a function to toggle all the bits except k-th bit. Here value of k starts from 0 (zero) and from right.

Examples:

```Input : n = 4294967295, k = 0
Output : 1
The number 4294967295 in 32 bits has all bits
set.  When we toggle all bits except last bit,
we get 1.

Input  :  n = 1, k = 1
Output : 4294967292
4294967262 has all bits toggled except second
bit from right.
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

1. Toggle bit at k-th position. We do it by finding a number with only k-th bit set (using 1 << k), then doing bitwise XOR of this number n.
2. Toggle all bits of number obtained above using ~ (Bitwise negation)

 `// C program to toggle all bits except kth bit ` `#include ` ` `  `// Returns a number with all bit toggled in n ` `// except k-th bit ` `unsigned ``int` `toggleAllExceptK(unsigned ``int` `n, ` `                            ``unsigned ``int` `k) ` `{ ` `   ``/* 1) Toggle k-th bit by doing n ^ (1 << k) ` `      ``2) Toggle all bits of the modified number */` `    ``return` `~(n ^ (1 << k)); ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``unsigned ``int` `n = 4294967295; ` `    ``unsigned ``int` `k = 0; ` `    ``printf``(``"%u"``, toggleAllExceptK( n, k)); ` `    ``return` `0; ` `} `

Output:

```1
```

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