Keep Only the Highest Set Bit

Code

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

uint16_t highest_set_bit(uint16_t reg) {
    if (reg == 0) return 0;  // special case: no set bits

    for (int i = 15; i >= 0; i--) {
        if (reg & (1 << i)) {
            return (1 << i);   // immediately return highest bit
        }
    }
    return 0; // not reached, but keeps compiler happy
}

int main() {
    uint16_t reg;
    scanf("%hu", &reg);
    uint16_t result = highest_set_bit(reg);
    printf("%hu\n", result);
    return 0;
}

Solving Approach