Extract Even Bits Only from 32-bit Register

Code

#include <stdio.h>
#include <stdint.h>

uint32_t extract_even_bits(uint32_t reg)
{
    // Step 1: Create mask with 1s in even positions
    uint32_t mask = 0;
    for(int i = 0; i < 32; i += 2){
        mask |= (1U << i);
    }

    // Step 2: Apply mask to extract even-position bits
    uint32_t filtered = reg & mask;

    // Step 3: Compress the even bits (remove gaps)
    uint32_t result = 0;
    int k = 0;

    for(int i = 0; i < 32; i += 2) {
        uint32_t bit = (filtered >> i) & 1U;   // extract bit at even position
        result |= (bit << k);                  // place contiguously into result
        k++;
    }

    return result;     // compressed 16-bit value inside 32-bit container
}


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

Solving Approach