fn main() {
let num = 42; // 00101010 in binary
// Count number of 1s in binary representation
let bit_count = format!("{:b}", num).chars().filter(|&ch| ch == '1').count();
let result = bit_count % 2;
println!("0 = even number of bits set");
println!("1 = odd number of bits set");
println!("result: {}", result);
}
/*
run:
0 = even number of bits set
1 = odd number of bits set
result: 1
*/