1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) 
{
    // Write your code here
    if(mode)
        return reg |= (1U<<pos);
    else
        return reg &= ~(1U<<pos);
}

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