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
    // reg = reg&0x55;
    // reg = ((reg >> 0) & 1) |
    //        ((reg >> 1) & 2) |
    //        ((reg >> 2) & 4) |
    //        ((reg >> 3) & 8);
    // return reg;
    uint32_t result = 0;
    int out_pos = 0;
    for (int in_pos = 0; reg != 0; in_pos += 2) {
        if (reg & 1) {
            result |= (1U << out_pos);
        }
        reg >>= 2;
        out_pos++;
    }
    return result;

}

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

Solving Approach