Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    if(reg == 0) return 0;
    uint16_t index = 15;
    uint16_t tester = 1<<index;
    while(!(tester & reg)){
        index --;
        tester = 1<<index;
    }
    
    reg = tester;
    return reg;
}

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

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

Solving Approach