Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    // Your logic here
    if(reg == 0) return 0; // special case: no bits set

    reg = reg | (reg >> 1);
    reg = reg | (reg >> 2);
    reg = reg | (reg >> 4);
    reg = reg | (reg >> 8);

    return (reg + 1) >> 1;
}

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

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

Solving Approach