Keep Only the Highest Set Bit

Code

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

// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    while(reg & (reg - 1)){
        reg = reg & (reg - 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

• Input: Read 16-bit number reg.
• Loop: While more than one bit is set →
  reg = reg & (reg - 1) (clears lowest set bit).
• Stop: When only one bit remains.
• Output: That bit → highest set bit.