1. Set or Clear a Specific Bit in a Register

#include <stdio.h>
uint8_t modifyBit(uint8_t reg, uint8_t pos, uint8_t mode) {
   if (mode == 1) {
       reg |= (1 << pos);  // Set bit
   } else {
       reg &= ~(1 << pos); // Clear bit
   }
   return reg;
}
int main() {
   uint8_t reg;
   uint8_t pos, mode;
   scanf("%hhu %d %d", &reg, &pos, &mode);
   printf("%huu", modifyBit(reg, pos, mode));
   return 0;
}