finish 3 simple c++ programs

# ifndef STACKLIB

# define STACKLIB

class STACK

{ private:int a[5];

int counter;

public:void ClearStack() { counter = 0; }

bool EmptyStack() {if (counter == 0) return true; else return false;}

bool FullStack() { return (counter == 5) ? true : false; }

void PushStack(int x) { a[counter] = x; counter++; }

int PopStack(){ counter--; return a[counter]; }

};

# endif