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 i;

    // for (i = 0; i < 16; i++) {
    //     if ((reg >> (15 - i)) & 1) {
    //         break;
    //     }
    // }
    // return i == 16? 0 : (1 << (15 - i));

    // solution (1-entry & 1-exit)
    uint16_t result = 1U << 15; // find the highest set bit.
    while (0 != reg && (reg & result) == 0) {
        result >>= 1;
    }
    return reg & result;
}

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

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

Solving Approach

Which one is better?

• I think the solution is better.