here is a simple circular queue program

Queue.h

@@ -0,0 +1,82 @@
+template <typename T>
+class Queue {
+    T *data;
+    int nextIndex;
+    int frontIndex;
+    int size;
+    int capacity;
+
+    public :
+
+    Queue() {
+        data = new T[5];
+        nextIndex = 0;
+        frontIndex = -1;
+        size = 0;
+        capacity = 5;
+    }
+
+    int getSize() {
+        return size;
+    }
+
+    bool isEmpty() {
+        return size == 0;
+    }
+
+    void enqueue(T element) {
+        if(size == capacity) {
+            // Queue full
+            // return;
+            T *temp = data;
+            data = new T[2 * capacity];
+            int j = 0;
+            for(int i = frontIndex; i < capacity; i++) {
+                data[j++] = temp[i];
+            }
+            for(int i = 0; i < frontIndex; i++) {
+                data[j++] = temp[i];
+            }
+            delete [] temp;
+            frontIndex = 0;
+            nextIndex = j;
+            capacity *= 2;
+        }
+        data[nextIndex] = element;
+        size++;
+        nextIndex = (nextIndex + 1) % capacity;
+        if(frontIndex == -1) {
+            frontIndex = 0;
+        }
+    }
+
+    T front() {
+        if(frontIndex == -1) {
+            // Queue empty
+            return 0;
+        }
+        return data[frontIndex];
+    }
+
+    T dequeue() {
+        if(frontIndex == -1) {
+            // Queue empty
+            return 0;
+        }
+        T ans = data[frontIndex];
+        frontIndex = (frontIndex + 1) % capacity;
+        size--;
+        if(size == 0) {
+            frontIndex = -1;
+            nextIndex = 0;
+        }
+        return ans;
+    }
+
+
+
+
+
+
+
+};

QueueUse.cpp

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+#include <iostream>
+using namespace std;
+#include "Queue.h"
+
+int main() {
+    Queue<int> q;
+    cout << q.getSize() << endl;
+
+    q.enqueue(10);
+    q.enqueue(20);
+    q.enqueue(30);
+    q.enqueue(40);
+    q.enqueue(50);
+    q.enqueue(60);
+
+    cout << q.front() << endl;
+
+    while(!q.isEmpty()) {
+        cout << q.dequeue() << endl;
+    }
+}
+