Set or Clear a Specific Bit in a Register

Code

#include <stdio.h>
#define set_bit(a, n) ( a | ( 1<<n ) )
#define clr_bit(a, n) ( a & ( ~( 1<<n ) ) ) 

unsigned char modifyBit(unsigned char reg, int pos, int mode) {
    
    if( mode )
    {
        reg = set_bit(reg, pos);
        return reg;
    }
    else
    {
        reg = clr_bit(reg, 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