22. Extract Even Bits Only from 32-bit Register

#include <stdio.h>
#include <stdint.h>

#define checkTrue(reg, pos) (reg >> pos) & 1

uint32_t extract_even_bits(uint32_t reg) {
    // Your code here
    uint32_t extracted = 0;
    for(int i=15;i>0;i--){
        extracted += checkTrue(reg, i*2);
        extracted <<= 1;
    }
    extracted += (reg & ((uint32_t)1<<0));
    return extracted;
}

int main() {
    uint32_t reg;
    scanf("%u", &reg);
    printf("%u", extract_even_bits(reg));
    return 0;
}