queue using 2 stacks

Author: joharbatta

Assignments/queuebystack.java

@@ -0,0 +1,70 @@
+import java.io.*;
+import java.util.*;
+
+public class queuebystack
+{
+   
+    Stack<Integer> s1 = new Stack<Integer>();
+    Stack<Integer> s2 = new Stack<Integer>();
+    void enqueue(int a)
+    {
+        s1.push(a);
+       
+    }
+    int dequeue()
+    {
+        if(s1.empty())
+        {
+            return 0;
+        }
+        while(!s1.empty())
+        {
+            s2.push(s1.pop());
+        }
+        int a = s2.pop();
+        while(!s2.empty())
+        {
+            s1.push(s2.pop());
+        }
+        
+        return a;
+    }
+    void show()
+    {
+        if(s1.empty())
+        {
+            System.out.println("Empty queue");
+            return;
+        }
+        while(!s1.empty())
+        {
+            s2.push(s1.pop());
+        }
+        while(!s2.empty())
+        {
+            int a = s2.peek();
+            s1.push(s2.pop());
+            System.out.print(a+" ");
+        }
+    }
+
+
+    public static void main(String []agrs)
+    {
+        queuebystack q = new queuebystack();
+        q.enqueue(1);
+        q.enqueue(2);
+        q.enqueue(3);
+        q.enqueue(4);
+        q.enqueue(5);
+        q.enqueue(6);
+        q.show();
+
+        //System.out.print(q.dequeue());
+        System.out.println("\n"+q.dequeue());
+        q.enqueue(7);
+        System.out.println(q.dequeue());
+        q.show();
+       
+    }
+}