22. Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
    // Your code here
    uint32_t res = 0;
    for (int i=30; i >= 0; i = i - 2)
    {
        res = (res | ((reg & (1 << i)) >> i)) << 1;
    }
    return (res >> 1);
}

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