Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    int left = 0;

    for(int i = 15; i >= 0; i--) {
        if (reg & (1u << i)) {
            left = i;
            break;
        }
    }

    uint16_t mask = ~((1u << left) - 1u);
    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