22. Extract Even Bits Only from 32-bit Register

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

uint16_t extract_even_bits(uint32_t reg)
{
    uint16_t result = 0;

    for (int i = 0; i < 16; i++)
    {
        if (reg & (1 << (2 * i)))
        {
            result |= (1 << i);
        }
    }

    return result;
}

int main()
{
    uint32_t reg;

    scanf("%u", &reg);

    printf("%u", extract_even_bits(reg));

    return 0;
}