Create Arraystack

Arrays/Arraystack

@@ -0,0 +1,80 @@
+public class Arraystack<E> implements Stack<E>
+{
+  public static final int CAPACITY=1000;
+  private E[] data;
+  private int t = -1;
+
+  public Arraystack()
+  {
+      	data= (E[]) new Object[CAPACITY];
+  }
+
+  public Arraystack(int capacity) {
+    	data= (E[]) new Object[capacity]; 
+  }
+
+  @Override
+  public int size() { return t+1; }
+
+  @Override
+  public boolean isEmpty() { return t==-1;  }
+
+  @Override
+  public void push(E e) throws IllegalStateException {
+    t++;
+    data[t]=e;
+
+  }
+
+  @Override
+  public E top() {
+    if(isEmpty())
+    return null;
+    return data[0];
+  }
+
+  @Override
+  public E pop() {
+    if(isEmpty())
+    {
+      System.out.println("OVERFLOW");
+      return null;
+    }
+    E d=data[t];
+    t--;
+    return d;
+  }
+
+  public String toString() {
+    StringBuilder sb = new StringBuilder("(");
+    for(int i=0;i<=t;i++)
+    {
+      sb.append(data[i]);
+      sb.append(", ");
+
+    }
+    sb.append(")");
+    return sb.toString();
+
+  }
+  public static void main(String[] args) {
+    Stack<Integer> S = new Arraystack<>();  
+    S.push(5);                              // contents: (5)
+    S.push(3);                              // contents: (5, 3)
+    System.out.println(S.size());           // contents: (5, 3)     outputs 2
+    System.out.println(S.pop());            // contents: (5)        outputs 3
+    System.out.println(S.isEmpty());        // contents: (5)        outputs false
+    System.out.println(S.pop());            // contents: ()         outputs 5
+    System.out.println(S.isEmpty());        // contents: ()         outputs true
+    System.out.println(S.pop());            // contents: ()         outputs null
+    S.push(7);                              // contents: (7)
+    S.push(9);                              // contents: (7, 9)
+    System.out.println(S.top());            // contents: (7, 9)     outputs 9
+    S.push(4);                              // contents: (7, 9, 4)
+    System.out.println(S.size());           // contents: (7, 9, 4)  outputs 3
+    System.out.println(S.pop());            // contents: (7, 9)     outputs 4
+    S.push(6);                              // contents: (7, 9, 6)
+    S.push(8);                              // contents: (7, 9, 6, 8)
+    System.out.println(S.pop());            // contents: (7, 9, 6)  outputs 8
+  }
+}