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 ans =0 ;
    int i;
    int j = 0;
    uint32_t ex;

    for(i=0;i<32;i=i+2){
        ex = reg & (0x01 << i);
        if(ex){
            ans = ans | 0x01<<j;
            j++;
        } 
        else {
            ans |= 0x00;
            j++;
        }
        
    }
    return ans;
}

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