22. Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
    // Your code here
    int j = 0;
    uint32_t res = 0;
    for(int i = 0; i<32; i+=2){
        if(reg &(1U<<i))
            res |= (1U << j);
        j++;
    }
    return res;
}

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