1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

int main() {
    unsigned char reg;
    int pos, mode;

    scanf("%hhu %d %d", &reg, &pos, &mode);

    if (mode == 1) {
        reg |= (1 << pos);     // Set bit
    }
    else if (mode == 0) {
        reg &= ~(1 << pos);    // Clear bit
    }

    printf("%u\n", reg);       // Print updated value

    return 0;
}