1. Set or Clear a Specific Bit in a Register

#include <stdio.h>
#include <cstdint>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
    uint8_t mask = 0x01 << pos;

    if (mode) {
        reg |= mask;  // set bit
    } else {
        reg &= ~mask; // clear bit
    }

    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;
}