chore: import upstream snapshot with attribution

data_structures/queue_using_array2.cpp

@@ -0,0 +1,56 @@
+#include <iostream>
+
+int queue[10];
+int front = 0;
+int rear = 0;
+
+void Enque(int x) {
+    if (rear == 10) {
+        std::cout << "\nOverflow";
+    } else {
+        queue[rear++] = x;
+    }
+}
+
+void Deque() {
+    if (front == rear) {
+        std::cout << "\nUnderflow";
+    }
+
+    else {
+        std::cout << "\n" << queue[front++] << " deleted";
+        for (int i = front; i < rear; i++) {
+            queue[i - front] = queue[i];
+        }
+        rear = rear - front;
+        front = 0;
+    }
+}
+
+void show() {
+    for (int i = front; i < rear; i++) {
+        std::cout << queue[i] << "\t";
+    }
+}
+
+int main() {
+    int ch, x;
+    do {
+        std::cout << "\n1. Enque";
+        std::cout << "\n2. Deque";
+        std::cout << "\n3. Print";
+        std::cout << "\nEnter Your Choice : ";
+        std::cin >> ch;
+        if (ch == 1) {
+            std::cout << "\nInsert : ";
+            std::cin >> x;
+            Enque(x);
+        } else if (ch == 2) {
+            Deque();
+        } else if (ch == 3) {
+            show();
+        }
+    } while (ch != 0);
+
+    return 0;
+}