1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned int modifyBit(unsigned int reg, int pos, int mode) {
    if(mode == 1) {
        return reg |= (1 << pos);
    } else if(mode == 0) {
        return reg &= ~(1 << pos);
    } else {
        printf("Invalid Operation\n");
        return -1;
    }
}

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

Observed the question and noticed that there was unsigned char instead of int, so I corrected that and performed the appropriate