1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {

 int value =0;
    if(mode)
    {
        value=(reg)|(1<<pos);
        return value;
    }
    else
    {
        value =(reg)&(~(1<<pos));
        return value;
    }

}

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