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
    uint8_t b = 0;
    uint16_t out = 0;
    //printf("reg: %32b\n",reg);
    for (int i =0; i<32; i+=2){
        //extract bit from position i
        b = ((reg & (1UL<<i))>>i);
        if(reg>>i){
        out = (out<<1);
       // printf("i=%d: out=%32b, b=%32b\n",i,out,b);
        out |= b;
        }
        

    }


    return out;
}

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

Solving Approach