Keep Only the Highest Set Bit

Code

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

uint16_t keep_highest_set_bit(uint16_t n) {
    if (n == 0) {
        return 0;
    }

    n |= n >> 1;
    n |= n >> 2;
    n |= n >> 4;
    n |= n >> 8;

    return n - (n >> 1);
}

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

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

Solving Approach