How to Remove an Element from a Set in C++?

In C++, sets are a type of associative container in which each element has to be unique. The values are stored in a specific sorted order i.e. either ascending or descending. In this article, we will see how to remove specific elements from a set in C++.

Example

Input: 
set = {100,120,12,56,78,9,32,45,78,44}
Deleting element = 56

Output:
{100,120,12,78,9,32,45,78,44}

Delete a Specific Element from a Set in C++

To delete a specific element from a set in C++, we can use the std::set::erase() function that is able to remove elements by using the value or iterator.

C++ Program to Remove an Element from a Set

C++

// C++ program to remove specific element from a set
#include <iostream>
#include <set>
using namespace std;

// Driver Code
int main()
{
    // Create Set with 10 integers
    set<int> set
        = { 100, 120, 12, 56, 78, 9, 32, 45, 78, 44 };
    cout << "Existing Set" << endl;
    for (auto element : set) {
        cout << element << " ";
    }

    // Remove 56 from the set using the erase() function
    set.erase(56);

    cout << endl;
    cout << "Final Set" << endl;
    for (auto element : set) {
        cout << element << " ";
    }

    return 0;
}

Output

Existing Set
9 12 32 44 45 56 78 100 120 
Final Set
9 12 32 44 45 78 100 120 

Time complexity: O(N)
Auxiliary Space: O(1)