1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
    if(mode)
    {
        int mask = (1<<pos);
        reg |= mask ; // setting the bits
    }
    else
    {
        int mask = (1<<pos) ;
        reg &= ~(1<<pos);

    }
    return reg ;
}

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