ImplementingQueueUsingLL.cpp

dsa/cpp/ImplementingQueueUsingLL.cpp

@@ -0,0 +1,101 @@
+// Implementing a Queue Data Structure specifically to store integer data using a Singly Linked List.
+
+//  code by Shreya Singhal
+#include <iostream>
+using namespace std;
+
+class Node {
+   public:
+    int data;
+    Node *next;
+
+    Node(int data) {
+        this->data = data;
+        next = NULL;
+    }
+};
+
+
+class Queue {
+	Node * head;
+    Node *tail;
+    int size;
+
+   public:
+    Queue() {
+        head = NULL;
+        tail= NULL;
+		size=0;        
+	}
+
+
+	int getSize() {
+		return size;
+	}
+
+    bool isEmpty() {
+		return (size==0);
+	}
+
+    void enqueue(int element) {
+		Node *newnode = new Node(element);
+        if(head==NULL){
+            head = newnode;
+            tail = newnode;
+	     }
+        else{
+            tail->next = newnode;
+            tail = newnode;
+        }
+        size++;
+    }
+
+    int dequeue() {
+        if(isEmpty()){
+            return -1;
+        }
+       int ans = head->data;
+        Node*temp = head;
+        head = head->next;
+        delete temp;
+        size--;
+        return ans;            
+    }
+
+    int front() {
+      if(isEmpty()){
+            return -1;
+        }
+        return head->data;
+    }
+};
+
+int main() {
+    Queue q;
+
+    int t;
+    cin >> t;
+
+    while (t--) {
+        int choice, input;
+        cin >> choice;
+        switch (choice) {
+            case 1:
+                cin >> input;
+                q.enqueue(input);
+                break;
+            case 2:
+                cout << q.dequeue() << "\n";
+                break;
+            case 3:
+                cout << q.front() << "\n";
+                break;
+            case 4:
+                cout << q.getSize() << "\n";
+                break;
+            default:
+                cout << ((q.isEmpty()) ? "true\n" : "false\n");
+                break;
+        }
+    }
+}