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

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