Queue in C++ STL - Sanfoundry

This C++ Program demonstrates implementation of Queue in STL.

Here is source code of the C++ Program to demonstrate Queue in STL. The C++ program is successfully compiled and run on a Linux system. The program output is also shown below.

```
/*
```

 * C++ Program to Implement Queue in Stl

```
 */
```
```
#include <iostream>
```
```
#include <queue>
```
```
#include <string>
```
```
#include <cstdlib>
```
```
using namespace std;
```
```
int main()
```
```
{
```
```
    queue<int> q;
```
```
    int choice, item;
```
```
    while (1)
```
```
    {
```

        cout<<"\n---------------------"<<endl;

        cout<<"Queue Implementation in Stl"<<endl;

        cout<<"\n---------------------"<<endl;

        cout<<"1.Insert Element into the Queue"<<endl;

        cout<<"2.Delete Element from the Queue"<<endl;

```
	cout<<"3.Size of the Queue"<<endl;
```

        cout<<"4.Front Element of the Queue"<<endl;

        cout<<"5.Last Element of the Queue"<<endl;

```
        cout<<"6.Exit"<<endl;
```
```
        cout<<"Enter your Choice: ";
```
```
        cin>>choice;
```
```
        switch(choice)
```
```
        {
```
```
        case 1:
```

            cout<<"Enter value to be inserted: ";

```
            cin>>item;
```
```
            q.push(item);
```
```
            break;
```
```
        case 2:
```
```
            item = q.front();
```
```
            q.pop();
```

            cout<<"Element "<<item<<" Deleted"<<endl;

```
            break;
```
```
        case 3:
```
```
	    cout<<"Size of the Queue: ";
```
```
	    cout<<q.size()<<endl;
```
```
            break;
```
```
        case 4:
```

            cout<<"Front Element of the Queue: ";

```
	    cout<<q.front()<<endl;
```
```
            break;
```
```
        case 5:
```

            cout<<"Back Element of the Queue: ";

```
            cout<<q.back()<<endl;
```
```
            break;
```
```
        case 6:
```
```
            exit(1);
```
```
	    break;
```
```
        default:
```
```
            cout<<"Wrong Choice"<<endl;
```
```
        }
```
```
    }
```
```
    return 0;
```
```
}
```

$ g++ queue.cpp
$ a.out
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1
Enter value to be inserted: 9
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1 
Enter value to be inserted: 8
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1
Enter value to be inserted: 7
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1
Enter value to be inserted: 6
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1
Enter value to be inserted: 5
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 1
Enter value to be inserted: 4
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 3
Size of the Queue: 6
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 4
Front Element of the Queue: 9
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 5
Back Element of the Queue: 4
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 2
Element 9 Deleted
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 3
Size of the Queue: 5
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 4
Front Element of the Queue: 8
 
---------------------
Queue Implementation in Stl
 
---------------------
1.Insert Element into the Queue
2.Delete Element from the Queue
3.Size of the Queue
4.Front Element of the Queue
5.Last Element of the Queue
6.Exit
Enter your Choice: 6
 
 
------------------
(program exited with code: 1)
Press return to continue