Keep Only the Highest Set Bit

Code

#include <stdio.h>
#include <stdint.h>
int highestBitPos(unsigned int x) {
    if (x == 0) return -1; // không có bit nào
    return 31 - __builtin_clz(x);
}
// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    // Your logic here
    int pos =31 - __builtin_clz (reg);
    uint16_t mask = 1U << pos;
    reg &= mask;
    return reg;
}

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

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

Solving Approach