Extract Even Bits Only from 32-bit Register

Code

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

uint32_t extract_even_bits(uint32_t reg) {
    // Your code here
    uint32_t test=0;
    int j=-1;
    for (int i=0;i<32;i++){
        if(i%2==0){
            j++;
            if (reg & (1 << i)){
                test |= (1<<j);
            }
            else {

            }
        }
    }
    return test;
}

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

Solving Approach