Function flip_bits 

pub fn flip_bits(n: usize, num: usize) -> usize

Flips the bits in num from ith position to (n-i)th position.

Example

use qip_iterators::utils::flip_bits;

assert_eq!(flip_bits(3, 0b100), 0b001);
assert_eq!(flip_bits(3, 0b010), 0b010);
assert_eq!(flip_bits(4, 0b1010), 0b0101);