Bit Spreading Interleave Bits with Zeros

Code

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

uint16_t spread_bits(uint8_t val) {
     uint16_t reg = val;

    // Step 1: spread bits by 4 positions
    reg = (reg | (reg << 4)) & 0x0F0F;

    // Step 2: spread bits by 2 positions
    reg = (reg | (reg << 2)) & 0x3333;

    // Step 3: spread bits by 1 position
    reg = (reg | (reg << 1)) & 0x5555;

    return reg;
}

int main() {
    uint8_t val;
    scanf("%hhu", &val);

    uint16_t result = spread_bits(val);
    printf("%u", result);
    return 0;
}

Solving Approach