rename Data Structure -> data_structure (#644)

data_structure/Queue Using Array.cpp

@@ -0,0 +1,75 @@
+#include <iostream>
+using namespace std;
+
+int queue[10];
+int front = 0;
+int rear = 0;
+
+void Enque(int x)
+{
+	if (rear == 10)
+	{
+		cout << "\nOverflow";
+	}
+	else
+	{
+		queue[rear++] = x;
+	}
+}
+
+void Deque()
+{
+	if (front == rear)
+	{
+		cout << "\nUnderflow";
+	}
+
+	else
+	{
+		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++)
+	{
+		cout << queue[i] << "\t";
+	}
+}
+
+int main()
+{
+	int ch, x;
+	do
+	{
+		cout << "\n1. Enque";
+		cout << "\n2. Deque";
+		cout << "\n3. Print";
+		cout << "\nEnter Your Choice : ";
+		cin >> ch;
+		if (ch == 1)
+		{
+			cout << "\nInsert : ";
+			cin >> x;
+			Enque(x);
+		}
+		else if (ch == 2)
+		{
+			Deque();
+		}
+		else if (ch == 3)
+		{
+			show();
+		}
+	} while (ch != 0);
+
+	return 0;
+}