Set or Clear a Specific Bit in a Register

Code

#include <stdio.h>

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
    reg = mode
        ? reg | (1u << pos)
        : reg & ~(1u << 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;
}

Solving Approach

The function modifies the register based on the mod value: if it's true it make a bitwise or with a singol 1 in the chosen position, otherwise it make a bitwise and with full zeros except a 1 in the chosen position, then return the value.