# Sets-STL in C++ HackerRank Solution

Nov 27, 2022

Hello Programmers, In this post, you will know how to solve the Sets-STL in C++ HackerRank Solution. This problem is a part of the HackerRank C++ Programming Series.

One more thing to add, don’t directly look for the solutions, first try to solve the problems of Hackerrank by yourself. If you find any difficulty after trying several times, then you can look for solutions.

## Sets-STL in C++ HackerRank Solution

### Problem

Sets are a part of the C++ STL. Sets are containers that store unique elements following a specific order. Here are some of the frequently used member functions of sets:
Declaration:

```set<int>s; //Creates a set of integers.
```

Size:

```int length=s.size(); //Gives the size of the set.
```

Insert:

```s.insert(x); //Inserts an integer x into the set s.
```

Erasing an element:

```s.erase(val); //Erases an integer val from the set s.
```

Finding an element:

```set<int>::iterator itr=s.find(val); //Gives the iterator to the element val if it is found otherwise returns s.end() .
Ex: set<int>::iterator itr=s.find(100); //If 100 is not present then it==s.end().
```

To know more about sets click Here. Coming to the problem, you will be given Q queries. Each query is of one of the following three types:

1. x: Add an element x to the set.
2. x: Delete an element x from the set. (If the number x is not present in the set, then do nothing).
3. x: If the number x is present in the set, then print “Yes”(without quotes) else print “No”(without quotes).

### Input Format :

The first line of the input contains Q where Q is the number of queries. The next Q lines contain 1 query each. Each query consists of two integers x and y where y is the type of the query and x is an integer.

### Constraints :

• 1 <= Q <= 10^5
• 1 <= y <= 3
• 1 <= x <= 10^9

### Output Format :

For queries of type 3 print “Yes”(without quotes) if the number x is present in the set and if the number is not present, then print “No”(without quotes).
Each query of type 3 should be printed in a new line.

```8
1 9
1 6
1 10
1 4
3 6
3 14
2 6
3 6
```

```Yes
No
No```

### Sets-STL in C++ HackerRank Solution

```#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <set>
#include <algorithm>
using namespace std;
int main()
{
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
/* Sets-STL in C++ - Hacker Rank Solution START */
set <int> s;
int N = 0, i;
cin >> N;
for (i = 0; i < N; i++)
{
int q = 0, x = 0;
cin >> q;
cin >> x;
if (q == 1)
{
s.insert(x);
}
else if (q == 2)
{
s.erase(x);
}
else
{
set<int>::iterator itr=s.find(x);
if (itr == s.end())
{
cout<<"No"<<endl;
}
else
{
cout<<"Yes"<<endl;
}
}
}
/* Sets-STL in C++ - Hacker Rank Solution END */
return 0;
}
```

Disclaimer: The above Problem (Sets-STL in C++) is generated by Hackerrank but the Solution is Provided by BrokenProgrammers. This tutorial is only for Educational and Learning purposes.