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 result=0;
    int out_pos=0;
    for(int i=0;i<32;i+=2){
        if((reg>>i)&1)result|=(1U<<out_pos);
        out_pos++;
    }
    return result;
}

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