Answer 1

I just use these
& - AND
~ - NOT
| - OR

From these you can make all the other gates
int Nand(int x, int y)
{
return ~ (x & y);
}

int Xor(int x, int y)
{
return (x & ~y) | (~x & y);
}

int Xnor(int x, int y)
{
return (x & y) | (~x & ~y);
}
Something like that. Just visualize them and get the diagrams (^_-)