Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
   int i;
   uint16_t ex;
   //ex = 0x8000;
   int flag;
   for(i=0;i<32;i++){
        ex = reg & 0x8000>>i;
        if(ex && flag == 0) flag = 1;
        else reg = reg & (~(0x8000>>i));
   }
   return reg;
}

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

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

Solving Approach