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
    // xuất bit từng bit chẵn --> kiểm tra 0 hay 1 sau đó tích vào biến
    uint32_t pre = reg;
    uint32_t reg_2;
    uint32_t reg_kq;
    for(int i =0; i <=31;i = i +2){
        reg = reg & (1<<i);// 00000001010
        reg_2 = (reg >> (i)); ///00000000001
        if(reg_2 ==1){
            reg_kq |= (1<<(i/2));
        }else if(reg_2 ==0){
            reg_kq |= (0<<(i/2));
        }
        reg = pre;
        reg_2 =0;
    }
    return reg_kq;
}

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