Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    for(int i =0 ; i <=15;i++){
        //If bit is set, then we immediately overwrite the rest with 0
        int mask = 1<<(15-i);
        if(reg&mask) {
            return mask; //We don't need to replace the rest, just output the mask.
            //This is because a bit mask is just testing all bits individually
        }
    }
    return reg;
}

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

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

Solving Approach