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 ret=0;
    int idx=0;
    for(int i=0; i<32; i+=2) {
        if((reg & (1 << i)) != 0) {
            ret |= (1<<idx);
            idx++;
        }
    }
    return ret;
}

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