1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
   unsigned char mask;
   unsigned char result;
     if (mode == 1){ //set bit 
        //create bit mask
        mask = 1<<pos; 
        result = mask |= reg;
     }
     if (mode == 0){
         mask = ~(1<<pos);
         result = mask &= reg;
     }
     return result;
}

int main() {
    unsigned char reg;
    int pos, mode;
    scanf("%hhu %d %d", &reg, &pos, &mode);
    printf("%d", modifyBit(reg, pos, mode));
    return 0;
}