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 mask = 0;
    int i,j =0;
    while(i <= 31){
        if(reg & (1 << i )){
            mask |= (1 << j);
            j++; 
        }
        i+=2;
    }
    return mask;
}

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

Solving Approach