/******************************************************************************

* Compilation: javac FixedCapacityStackOfStrings.java

* Execution: java FixedCapacityStackOfStrings

* Dependencies: StdIn.java StdOut.java

*

* Stack of strings implementation with a fixed-size array.

*

* % more tobe.txt

* to be or not to - be - - that - - - is

*

* % java FixedCapacityStackOfStrings 5 < tobe.txt

* to be not that or be

*

* Remark: bare-bones implementation. Does not do repeated

* doubling or null out empty array entries to avoid loitering.

*

******************************************************************************/

import java.util.Iterator;

import java.util.NoSuchElementException;

public class FixedCapacityStackOfStrings implements Iterable<String> {

private String[] a; // holds the items

private int N; // number of items in stack

// create an empty stack with given capacity

public FixedCapacityStackOfStrings(int capacity) {

a = new String[capacity];

N = 0;

}

public boolean isEmpty() { return N == 0; }

public boolean isFull() { return N == a.length; }

public void push(String item) { a[N++] = item; }

public String pop() { return a[--N]; }

public String peek() { return a[N-1]; }

public Iterator<String> iterator() { return new ReverseArrayIterator(); }

public class ReverseArrayIterator implements Iterator<String> {

private int i = N-1;

public boolean hasNext() {

return i >= 0;

}

public String next() {

if (!hasNext()) throw new NoSuchElementException();

return a[i--];

}

public void remove() {

throw new UnsupportedOperationException();

}

}

public static void main(String[] args) {

int max = Integer.parseInt(args[0]);

FixedCapacityStackOfStrings stack = new FixedCapacityStackOfStrings(max);

while (!StdIn.isEmpty()) {

String item = StdIn.readString();

if (!item.equals("-")) stack.push(item);

else if (stack.isEmpty()) StdOut.println("BAD INPUT");

else StdOut.print(stack.pop() + " ");

}

StdOut.println();

// print what's left on the stack

StdOut.print("Left on stack: ");

for (String s : stack) {

StdOut.print(s + " ");

}

StdOut.println();

}

}