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 mask = 0;
    uint32_t result = 0;
    for(int i = 0; i < 16; i++) {
        mask = 1 << (i * 2);
        if(reg & mask) {
            result |= 1 << i;
        }
    }
    return result;
}

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