22. Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
    uint32_t out = 0;

    for (int i = 0; i < 32; i += 2) {
        out |= ((reg & (1 << i)) != 0) << (i / 2);
    }

    return out;
}

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