Create queue_using_stack.cpp

Author: kasyap1234

implement-queue-using-stacks/queue_using_stack.cpp

@@ -0,0 +1,41 @@
+
+class MyQueue {
+public:
+    stack<int> temp, ans;
+    /** Initialize your data structure here. */
+    MyQueue() {
+        
+    }
+    
+    /** Push element x to the back of queue. */
+    void push(int x) {
+        temp.push(x);
+    }
+    
+    /** Removes the element from in front of queue and returns that element. */
+    int pop() {
+        // shift input to output 
+        if (ans.empty())
+            while (temp.size())
+                ans.push(temp.top()), temp.pop();
+
+        int x = ans.top();
+        ans.pop(); 
+        return x; 
+    }
+    
+    /** Get the front element. */
+    int peek() {
+        // shift input to output 
+        if (ans.empty())
+            while (temp.size())
+                ans.push(temp.top()), temp.pop();
+        return ans.top(); 
+    }
+    
+    /** Returns whether the queue is empty. */
+    bool empty() {
+        return temp.empty() && ans.empty();
+    }
+
+};