[FEAT] first version of queue solution in cpp

challenges/easy/queue/solutions/aorlando/cpp-version/README.md

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+# Queue - How does it work?
+
+Queues follow the First-in-First-Out ([FIFO](https://it.wikipedia.org/wiki/FIFO)) principle.
+
+***e.g.*** As if waiting in a queue for the movie tickets, the first one to stand in line is the first one to buy a ticket and enjoy the movie.
+
+I have created a data structure in cpp for a queue able to do the following methods:
+
+  - `enqueue(item)` - adds an item to the queue
+  - `dequeue()` - removes an item from the queue (FIFO)
+  - `peek()` - returns the next item in the queue without removing it
+  - `isEmpty()` - tests to see whether the queue is empty
+  - `size()` - returns the number of items in the queue
+  - `display()` - return the item inside the queue
+
+
+  I've also tryed to develop a fancy CLI interface to insert the intructions directly from the user :)

challenges/easy/queue/solutions/aorlando/cpp-version/queue.cpp

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+#include <iostream>
+#include <vector>
+using namespace std;
+
+class Queue 
+{
+    private:
+    vector<int> myQueue;
+
+    public:
+
+    void enqueue(int item) {
+        myQueue.push_back(item);
+    }
+
+    int dequeue() {
+        int x = myQueue.at(0);
+        myQueue.erase(myQueue.begin()); 
+        return x;
+    }
+
+    int peek() {
+        return myQueue.at(0);
+    }
+
+    bool isEmpty() {
+        return myQueue.size() == 0;
+    }
+
+    int size() {
+        return myQueue.size();
+    }
+
+    vector<int> display() {
+        return myQueue;
+    }
+};
+
+
+int main() {
+    Queue test1;
+    int option, item;
+    vector<int> queue;
+
+    do {
+        cout << "\n\nWhat operation do you want to perform? Select Option number (0 to exit)." << endl;
+        cout << "1. enqueue(item)" << endl;
+        cout << "2. dequeue()" << endl;
+        cout << "3. peek()" << endl;
+        cout << "4. isEmpty()" << endl;
+        cout << "5. size()" << endl;
+        cout << "6. display()" << endl;
+
+
+        cin >> option;
+
+        switch(option) {
+            case 0:
+                break;
+
+            case 1:
+                cout << "*** Enqueue Operation *** \nPlease add an item to Queue:"<<endl;
+                cin >> item;
+                test1.enqueue(item);
+                break;
+
+            case 2:
+                if(test1.isEmpty())
+                    cout << "Queue is Empty" << endl;
+                else
+                    cout << "*** Dequeue Operation ***\nDequeued item: " << test1.dequeue() <<endl;
+                break;
+
+            case 3:
+                if(test1.isEmpty())
+                    cout << "Queue is Empty" << endl;
+                else
+                    cout << "*** Peek Operation ***\nThe first item inserted in Queue is: " << test1.peek() <<endl;
+                break;
+
+            case 4:
+                if(test1.isEmpty())
+                    cout << "Queue is Empty." << endl;
+                else
+                    cout << "Queue is NOT Empty." << endl;
+                break;
+
+            case 5:
+                cout << "*** Size Operation *** \nCount of items in Queue: " << test1.size() <<endl;
+                break;
+
+            case 6:
+                if(test1.isEmpty())
+                    cout << "Queue is Empty" << endl;
+                else {
+                    cout << "*** Display Function Called *** \nAll items in the Queue are: ";
+                    queue = test1.display();
+                    cout << "|";
+                    for(int i = 0; i < queue.size(); i++) {
+                        cout << queue[i] << "|";
+                    }
+                }
+                break;
+
+            default:
+                cout << "Please enter a valid option number. " << endl;
+                break;
+        }
+    }
+    while(option!=0);
+
+    return 0;
+}