Unordered_set in C++

This C++ Program demonstrates the implementation of Unordered_setin STL.

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

```
/*
```

 * C++ Program to Implement Unordered_set in STL

```
 */
```
```
#include <iostream>
```
```
#include <string>
```
```
#include <cstdlib>
```
```
#include <unordered_set>
```
```
using namespace std;
```
```
int main()
```
```
{
```

    unordered_set<string> myset = {"Mercury","Venus","Earth", "Mars","Jupiter","Saturn","Uranus"};

    unordered_set<string>::const_iterator got;

```
    unordered_set<string>::iterator it;
```
```
    int choice, item;
```
```
    string s;
```
```
    while (1)
```
```
    {
```

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

        cout<<"Unordered Set Implementation in Stl"<<endl;

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

```
        cout<<"1.Insert Element"<<endl;
```
```
        cout<<"2.Delete Element"<<endl;
```
```
        cout<<"3.Find Element"<<endl;
```
```
        cout<<"4.Count Elements"<<endl;
```

        cout<<"5.Size of the Unordered Set"<<endl;

        cout<<"6.Count number of Buckets"<<endl;

```
        cout<<"7.Buckets"<<endl;
```

        cout<<"8.Display Unordered Set"<<endl;

```
        cout<<"9.Exit"<<endl;
```
```
        cout<<"Enter your Choice: ";
```
```
        cin>>choice;
```
```
        switch(choice)
```
```
        {
```
```
        case 1:
```

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

```
            cin>>s;
```
```
            myset.insert(s);
```
```
            break;
```
```
        case 2:
```

            cout<<"Enter string to be deleted: ";

```
            cin>>s;
```
```
            myset.erase(s);
```
```
            break;
```
```
        case 3:
```

            cout<<"Enter key string to find ";

```
            cin>>s;
```
```
            got = myset.find (s);
```
```
            if (got == myset.end())
```

                cout<<"Element found in myset"<<endl;

```
            else
```

                cout<<"Element not found in myset"<<endl;

```
            break;
```
```
        case 4:
```

            cout<<"Enter string to be counted: ";

```
            cin>>s;
```

            cout<<"There are "<<myset.count(s)<<" elements with '"<<s<<"'\n";

```
            break;
```
```
        case 5:
```

            cout<<"Size of the Unordered Set: "<<myset.size()<<endl;

```
            break;
```
```
        case 6:
```

            cout<<"myset has "<< myset.bucket_count()<<" buckets.\n";

```
            break;
```
```
        case 7:
```

            for (const string& x: myset)

```
            {
```

                cout<< x <<" is in bucket #" << myset.bucket(x) << endl;

```
            }
```
```
            break;
```
```
        case 8:
```

            cout<<"Elements of the Unordered Set:  ";

            for (it = myset.begin(); it != myset.end(); ++it)

```
                cout << " " << *it;
```
```
            cout<<endl;
```
```
            break;
```
```
	case 9:
```
```
            exit(1);
```
```
	    break;
```
```
        default:
```
```
            cout<<"Wrong Choice"<<endl;
```
```
        }
```
```
    }
```
```
    return 0;
```
```
}
```

$ g++ unorderedset_stl.cpp
$ a.out
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 1
Enter string to be inserted: Neptune
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 1
Enter string to be inserted: Pluto
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 5
Size of the Unordered Set: 9
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 8
Elements of the Unordered Set:   Neptune Uranus Mercury Pluto Venus Mars Jupiter Earth Saturn
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 2
Enter string to be deleted: Earth
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 5
Size of the Unordered Set: 8
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 7
Neptune is in bucket #16
Uranus is in bucket #9
Mercury is in bucket #2
Pluto is in bucket #15
Venus is in bucket #15
Mars is in bucket #5
Jupiter is in bucket #7
Saturn is in bucket #4
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 7
myset has 17 buckets.
 
---------------------
Unordered Set Implementation in Stl
 
---------------------
1.Insert Element
2.Delete Element
3.Find Element
4.Count Elements
5.Size of the Unordered Set
6.Count number of Buckets
7.Buckets
8.Display Unordered Set
9.Exit
Enter your Choice: 9
 
------------------
(program exited with code: 1)
Press return to continue

Sanfoundry Global Education & Learning Series – 1000 C++ Programs.

If you wish to look at all C++ Programming examples, go to C++ Programs.

« Prev - C++ Program to Implement Unordered_multiset in STL

» Next - C++ Program to Implement Sorting Containers in STL

Related Posts:

Practice Design & Analysis of Algorithms MCQ
Check Computer Science Books
Practice Programming MCQs
Check Programming Books
Check Data Structure Books

Recommended Articles: