1 class Stack
2 {
3 private int top;
4 private int[] a;
5
6 public Stack(int size)
7 {
8 this.top = -1;
9 this.a = new int[size];
10 }
11
12 public boolean isFull()
13 {
14 /*if(this.top == this.a.length - 1)
15 return true;
16 else
17 return false;*/
18 return this.top == this.a.length - 1;
19 }
20
21 public boolean isEmpty()
22 {
23 return this.top == -1;
24 }
25
26 public void push(int k) throws Exception
27 {
28 if(this.isFull())
29 throw new Exception("Overflow.");
30 else
31 this.a[++top] = k;
32 }
33
34 public int pop() throws Exception
35 {
36 if(this.isEmpty())
37 throw new Exception("Underflow.");
38 else
39 return this.a[top--];
40 }
41 }
