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 mask = 0x8000;

    while (mask > 0) {
    if (reg & mask) {
       reg = mask;
       break;
    }
    mask >>= 1;
}
    return reg;
}

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

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

Solving Approach

Created a mask with set bit at MSB for 16bit unsigned integer.  If the first set bit is reached, assign mask to reg to make the remaining bits of reg cleared.