Compress Interleaved Bits Reverse Bit Spreading

Code

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

uint8_t compress_bits(uint16_t val) {
    uint8_t res = 0;
    for(int i = 0; i < 16; i += 2){
        uint8_t idx = (val >> i) & 1;
        uint8_t pos = i / 2;
        idx = (idx << pos);
        res |= idx;
    }    
    return res;
}

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

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

Solving Approach