1. Set or Clear a Specific Bit in a Register

#include <stdio.h>
int main() {
    unsigned char reg;
    int bit,mode;
    scanf("%hhu", &reg);
    scanf("%d", &bit);
    scanf("%d", &mode);
    if (mode == 1)
    reg = reg | (1 << bit);
    else
    reg = reg& ~(1 << bit);
    printf("%u\n", reg);
    return 0;
}