implement queue using LL

.vscode/settings.json

@@ -20,6 +20,8 @@
     "complex": "cpp",
     "iostream": "cpp",
     "cmath": "cpp",
-    "*.tcc": "cpp"
+    "*.tcc": "cpp",
+    "any": "cpp",
+    "type_traits": "cpp"
   }
 }

Striver Sheet/Day-13/Implement Queue using Linked List.cpp

@@ -0,0 +1,99 @@
+/*
+Implement Queue using Linked List
+=================================
+
+Implement a Queue using Linked List. 
+A Query Q is of 2 Types
+(i) 1 x   (a query of this type means  pushing 'x' into the queue)
+(ii) 2     (a query of this type means to pop an element from the queue and print the poped element)
+
+Example 1:
+Input:
+Q = 5
+Queries = 1 2 1 3 2 1 4 2
+Output: 2 3
+Explanation: n the first testcase
+1 2 the queue will be {2}
+1 3 the queue will be {2 3}
+2   poped element will be 2 the
+    queue will be {3}
+1 4 the queue will be {3 4}
+2   poped element will be 3.
+
+Example 2:
+Input:
+Q = 4
+Queries = 1 2 2 2 1 3 
+Output: 2 -1
+Explanation: In the second testcase 
+1 2 the queue will be {2}
+2   poped element will be {2} then
+    the queue will be empty. 
+2   the queue is empty and hence -1
+1 3 the queue will be {3}.
+
+Your Task:
+Complete the function push() which takes an integer as input parameter and pop() which will remove and return an element(-1 if queue is empty).
+
+Expected Time Complexity: O(1).
+Expected Auxiliary Space: O(1).
+
+Constraints:
+1 <= Q <= 100
+1 <= x <= 100
+*/
+
+/* Structure of a node in Queue
+struct QueueNode
+{
+    int data;
+    QueueNode *next;
+    QueueNode(int a)
+    {
+        data = a;
+        next = NULL;
+    }
+};
+
+And structure of MyQueue
+struct MyQueue {
+    QueueNode *front;
+    QueueNode *rear;
+    void push(int);
+    int pop();
+    MyQueue() {front = rear = NULL;}
+}; */
+
+//Function to push an element into the queue.
+void MyQueue::push(int x)
+{
+  QueueNode *nN = new QueueNode(x);
+  if (!front && !rear)
+  {
+    front = nN;
+    rear = nN;
+  }
+  else
+  {
+    rear->next = nN;
+    rear = nN;
+  }
+}
+
+//Function to pop front element from the queue.
+int MyQueue ::pop()
+{
+  if (front == NULL)
+    return -1;
+  int ans = front->data;
+  if (front == rear)
+  {
+    front = NULL;
+    rear = NULL;
+  }
+  else
+  {
+    front = front->next;
+  }
+  return ans;
+}

Striver Sheet/README.md

@@ -114,7 +114,7 @@
 - [Implement stack using array](https://practice.geeksforgeeks.org/problems/implement-stack-using-array/1#) - [Cpp Soultion](./Day-13/Implement%20stack%20using%20array.cpp)
 - [Implement Queue using array](https://practice.geeksforgeeks.org/problems/implement-queue-using-array/1#) - [Cpp Soultion](./Day-13/Implement%20Queue%20using%20array.cpp)
 - [Implement Stack using Linked List](https://practice.geeksforgeeks.org/problems/implement-stack-using-linked-list/1) - [Cpp Soultion](./Day-13/Implement%20Stack%20using%20Linked%20List.cpp)
-- []() - [Cpp Soultion](./Day-13/.cpp)
+- [Implement Queue using Linked List](https://practice.geeksforgeeks.org/problems/implement-queue-using-linked-list/1) - [Cpp Soultion](./Day-13/Implement%20Queue%20using%20Linked%20List.cpp)
 - []() - [Cpp Soultion](./Day-13/.cpp)
 - []() - [Cpp Soultion](./Day-13/.cpp)
 - []() - [Cpp Soultion](./Day-13/.cpp)