1. Set or Clear a Specific Bit in a Register

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
    // Write your code here
    if ((bool)mode)
        reg |= (1 << pos);
    else
        reg &= (0xff ^ (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;
}

No conflicts in datatypes in RHS and LHS.

for conditional verification of int, I will be typecasting it to bool adhering to MISRA C standards.

to set a value, we can always use | (OR) operator, but to reset a value, we need to mask the register except that position.