Compress Interleaved Bits Reverse Bit Spreading

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

uint8_t compress_bits(uint16_t val) {
    uint8_t result = 0;
    // We loop 8 times because we are extracting 8 specific bits
    for (int i = 0; i < 8; i++) {
        // 1. Find the bit at the even position (i * 2)
        // 2. Shift it down to the 0th position: (val >> (i * 2))
        // 3. Mask it so we only have that one bit: & 1
        // 4. Shift it to its new compact position: << i
        // 5. Combine it with the result using bitwise OR
        result |= ((val >> (i * 2)) & 1) << i;
    }
    return result;
}

int main() {
    uint16_t val;
    if (scanf("%hu", &val) == 1) {
        uint8_t result = compress_bits(val);
        printf("%u", result);
    }
    return 0;
}