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
    if (reg == 0) return 0;

    // Propagate the highest set bit to all lower bits
    reg |= (reg >> 1);
    reg |= (reg >> 2);
    reg |= (reg >> 4);
    reg |= (reg >> 8);

    // Clear all but the highest set bit
    return reg - (reg >> 1);
}

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

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

Solving Approach