Bit Spreading Interleave Bits with Zeros

Code

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

uint16_t spread_bits(uint8_t val) {
    // Your logic here
    uint16_t res = val;
    /*
    volatile char i;
    for(i=0;i<8;i++){
        if(val&(1<<i)){
            res |= (1<<(2*i));
        }
    }
    
    return res;*/
    res = (res|(res<<4)) & 0x0F0F;
    res = (res|(res<<2)) & 0x3333;
    res = (res|(res<<1)) & 0x5555;
    return res;

}

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

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

Solving Approach

    res = (res|(res<<4)) & 0x0F0F; This shifts the bits by 4 places and then keeps it in an order such that 4 bits appear together.

 res = (res|(res<<2)) & 0x3333; This shifts the bits by 2 places and then keeps it in an order such that 2 bits appear together.

  res = (res|(res<<1)) & 0x5555; This shift the bits by 1 and then keeps in the order we need to attain 1 bit followed by 0.