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 result = 0;
    uint32_t inputMask = 1U;
    uint32_t outputMask = 1U;
    while(inputMask) {
        if (reg & inputMask) {
            result |= outputMask;
        }
        inputMask <<= 2;
        outputMask <<= 1;
    }

    return result;
}

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