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surajr · surajr · commit b1ae2f902bb0 · 2017-10-21T18:58:07.000-07:00
diff --git a/java/QueueUsingStacks.java b/java/QueueUsingStacks.java
@@ -0,0 +1,50 @@
+class MyQueue {
+
+    Stack<Integer> stack;
+    Stack<Integer> queue;
+    
+    /** Initialize your data structure here. */
+    public MyQueue() {
+        stack = new Stack<>();
+        queue = new Stack<>();
+    }
+    
+    /** Push element x to the back of queue. */
+    public void push(int x) {
+        stack.push(x);
+    }
+    
+    /** Removes the element from in front of queue and returns that element. */
+    public int pop() {
+        if(queue.isEmpty())
+        {
+            while(!stack.isEmpty())
+                queue.push(stack.pop());
+        }
+        return queue.pop();
+    }
+    
+    /** Get the front element. */
+    public int peek() {
+        if(queue.isEmpty())
+        {
+            while(!stack.isEmpty())
+                queue.push(stack.pop());
+        }
+        return queue.peek();
+    }
+    
+    /** Returns whether the queue is empty. */
+    public boolean empty() {
+        return stack.isEmpty() && queue.isEmpty();
+    }
+}
+
+/**
+ * Your MyQueue object will be instantiated and called as such:
+ * MyQueue obj = new MyQueue();
+ * obj.push(x);
+ * int param_2 = obj.pop();
+ * int param_3 = obj.peek();
+ * boolean param_4 = obj.empty();
+ */
