Compress Interleaved Bits Reverse Bit Spreading

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

uint8_t compress_bits(uint16_t val) {
    // Your logic here
    uint16_t res = val & 0x5555; // extract even bits
    res = (res | (res >> 1)) & 0x3333; // 1 bit
    res = (res | (res >> 2)) & 0x0F0F; // 2 bit
    res = (res | (res >> 4)) & 0x00FF; // 4 bit

    return (uint8_t)res;
}

int main() {
    uint16_t val;
    scanf("%hu", &val);

    uint8_t result = compress_bits(val);
    printf("%u", result);
    return 0;
}