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 full = reg | reg >> 1;
    full |= full >> 2;
    full |= full >> 4;
    full |= full >> 8;
    full |= full >> 16;

    uint16_t mask = (full + 1) >> 1;
    return reg & mask;
}

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

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

Solving Approach