added Stack reverse

Program's_Contributed_By_Contributors/Java_Programs/Data_structure/Stack reverse.java

@@ -0,0 +1,84 @@
+import java.util.Stack;
+
+class Test {
+
+    // using Stack class for
+    // stack implementation
+    static Stack<Character> st = new Stack<>();
+
+    // Below is a recursive function
+    // that inserts an element
+    // at the bottom of a stack.
+    static void insert_at_bottom(char x)
+    {
+
+        if (st.isEmpty())
+            st.push(x);
+
+        else {
+
+            // All items are held in Function
+            // Call Stack until we reach end
+            // of the stack. When the stack becomes
+            // empty, the st.size() becomes 0, the
+            // above if part is executed and
+            // the item is inserted at the bottom
+            char a = st.peek();
+            st.pop();
+            insert_at_bottom(x);
+
+            // push allthe items held
+            // in Function Call Stack
+            // once the item is inserted
+            // at the bottom
+            st.push(a);
+        }
+    }
+
+    // Below is the function that
+    // reverses the given stack using
+    // insert_at_bottom()
+    static void reverse()
+    {
+        if (st.size() > 0) {
+
+            // Hold all items in Function
+            // Call Stack until we
+            // reach end of the stack
+            char x = st.peek();
+            st.pop();
+            reverse();
+
+            // Insert all the items held
+            // in Function Call Stack
+            // one by one from the bottom
+            // to top. Every item is
+            // inserted at the bottom
+            insert_at_bottom(x);
+        }
+    }
+
+    // Driver Code
+    public static void main(String[] args)
+    {
+
+        // push elements into
+        // the stack
+        st.push('1');
+        st.push('2');
+        st.push('3');
+        st.push('4');
+
+        System.out.println("Original Stack");
+
+        System.out.println(st);
+
+        // function to reverse
+        // the stack
+        reverse();
+
+        System.out.println("Reversed Stack");
+
+        System.out.println(st);
+    }
+}