package stack;

public class BoundedStack implements Stack {

private final int capacity;

private int elements[];

public static Stack Make(int capacity) {

if (capacity < 0) throw new IllegalCapacity();

if (capacity == 0) return new ZeroCapacityStack();

return new BoundedStack(capacity);

}

private BoundedStack(int capacity) {

this.capacity = capacity;

elements = new int[capacity];

}

private int size = 0;

public boolean isEmpty() {

return size == 0;

}

public int getSize() {

return size;

}

public void push(int element) {

if (size == capacity) throw new Overflow();

this.elements[size++] = element;

}

public int pop() {

if (isEmpty()) throw new Underflow();

return elements[--size];

}

public int top() {

if (isEmpty()) throw new Empty();

return elements[size-1];

}

public Integer find(int element) {

for (int i=size-1; i>=0; i--){

if (elements[i] == element)

return (size-1)-i;

}

return null;

}

private static class ZeroCapacityStack implements Stack {

@Override

public boolean isEmpty() {

return true;

}

@Override

public int getSize() {

return 0;

}

@Override

public void push(int element) {

throw new Overflow();

}

@Override

public int pop() {

throw new Underflow();

}

@Override

public int top() {

throw new Empty();

}

@Override

public Integer find(int element) {

throw null;

}

}

}