1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

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

    if (pos < 0 || pos > 7) {
        printf("Invalid bit position\n");
        return 0;
    }
    else if(mode==1)
    {
    reg|=(1<<pos);
    return reg;
    }
    else
    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;
}