rename folder to data_structures

data_structures/circular_queue_using_linked_list.cpp

@@ -0,0 +1,71 @@
+#include <iostream>
+using namespace std;
+
+struct node {
+    int data;
+    struct node *next;
+};
+class Queue {
+    node *front;
+    node *rear;
+
+ public:
+    Queue() {
+        front = NULL;
+        rear = NULL;
+    }
+    void createNode(int val) {
+        node *ptr;
+        node *nn;
+        nn = new node;
+        ptr = front;
+        nn->data = val;
+        nn->next = NULL;
+        front = nn;
+        rear = nn;
+    }
+    void enqueue(int val) {
+        if (front == NULL || rear == NULL) {
+            createNode(val);
+        } else {
+            node *ptr;
+            node *nn;
+            ptr = front;
+            nn = new node;
+            nn->data = val;
+            rear->next = nn;
+            nn->next = front;
+            rear = nn;
+        }
+    }
+    void dequeue() {
+        node *n;
+        n = front;
+        front = front->next;
+        delete (n);
+    }
+    void traverse() {
+        node *ptr;
+        ptr = front;
+        do {
+            cout << ptr->data << " ";
+            ptr = ptr->next;
+        } while (ptr != rear->next);
+        cout << front->data;
+        cout << endl;
+    }
+};
+int main(void) {
+    Queue q;
+    q.enqueue(10);
+    q.enqueue(20);
+    q.enqueue(30);
+    q.enqueue(40);
+    q.enqueue(50);
+    q.enqueue(60);
+    q.enqueue(70);
+    q.traverse();
+    q.dequeue();
+    q.traverse();
+    return 0;
+}