Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    uint16_t mask = 0x8000;
    while(1)
    {
       if((mask&reg) == mask)
         return mask;
       else
         mask = mask >> 1;
    }
    //if (reg == 0) return 0;
    //return 1u << ((int)(8 * sizeof(unsigned)) - 1 - __builtin_clz((unsigned)reg));
}

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

    uint16_t result = highest_set_bit(reg);
    printf("%hu", result);
    return 0;
}

Solving Approach