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
    uint16_t ret_val = reg;
    while((reg & (reg-1)) != 0 ){
        reg = reg & (reg-1);
        ret_val = reg;
    }
    return ret_val;
    /*
    //check for zero
    
    ret_val = 1U << 15;
    if(reg == 0)    return 0;
    while(!(reg & ret_val)){
        ret_val >>= 1;
    }
    return ret_val;
    */
}

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

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

Solving Approach

refer previous problem, isolate the leftmost bit by using bitwise anding operation or by checking each value until bitwise result is 0.