37. Compress Interleaved Bits Reverse Bit Spreading

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

uint8_t compress_bits(uint16_t val) {
    // Your logic here
    val &= 0x5555;
    val = (val | val >> 1) & 0x3333;
    val = (val | val >> 2) & 0x0F0F;
    val = (val | val >> 4) & 0x00FF;
    return (uint8_t)val;
}

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

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

The question is little wrong. It should be b7 b6 b5 b4 b3 b2 b1 b0.