How to delete an element from the Set by passing its value in C++

Difficulty Level : Basic
Last Updated : 01 Jun, 2021

Given a Set, the task is to remove the last element from this Set in C++.
Examples:

Input: set = [10 20 30 70 80 90 100 40 50 60],
              valueOfElementToBeDeleted = 100
Output: 10 20 30 40 50 60 70 80 90

Input: set = [1 2 3 4 5],
              valueOfElementToBeDeleted = 3
Output: 1 2 4 5

Sets are a type of associative container in which each element has to be unique because the value of the element identifies it. The value of the element cannot be modified once it is added to the set, though it is possible to remove and add the modified value of that element.
Approach: In this method, the last element is deleted by using the erase function and calling it with the value of the last element as its argument. If the value of the last element is not known, then use the previous method.
Syntax:

size_type erase (const value_type& valueOfElementToBeDeleted);

Below is the implementation of the above approach:

C++

// C++ program to delete an element
// of a Set by passing its value
 
#include <iostream>
#include <set>
using namespace std;
 
// Function to print the set
void printSet(set<int> myset)
{
 
    // Get the iterator
    set<int>::iterator it;
 
    // printing all the elements of the set
    for (it = myset.begin(); it != myset.end(); ++it)
        cout << ' ' << *it;
    cout << '\n';
}
 
// Function to delete the element of set
void deleteByValue(set<int> myset,
           int valueOfElementToBeDeleted)
{
 
    // printing all the elements of the set
    cout << "\nSet originally: ";
    printSet(myset);
 
    // Erase the element that is equal to
    // the value passed as the parameter
    myset.erase(valueOfElementToBeDeleted);
 
    // printing all the elements of the set
    cout << "Set after deleting "
         << valueOfElementToBeDeleted
         << ": ";
    printSet(myset);
}
 
// Driver code
int main()
{
    set<int> myset;
 
    // Get the set
    for (int i = 1; i < 10; i++)
        myset.insert(i * 10);
 
    // Get the valueOfElementToBeDeleted
    int valueOfElementToBeDeleted = 50;
 
    // Delete an element from the Set
    deleteByValue(myset, valueOfElementToBeDeleted);
 
    return 0;
}

Java

// Java program to delete an element
// of a Set by passing its value
import java.io.*;
import java.util.*;
class GFG
{
 
  // Function to print the set
  static void printSet(TreeSet<Integer> myset)
  {
 
    // printing all the elements of the set
    for(int it : myset)
    {
      System.out.print(it + " ");
    }
    System.out.println();
  }
 
  // Function to delete the element of set
  static void deleteByValue(TreeSet<Integer> myset, 
                            int valueOfElementToBeDeleted)
  {
 
    // printing all the elements of the set
    System.out.print("\nSet originally: ");
    printSet(myset);
 
    // Erase the element that is equal to
    // the value passed as the parameter
    myset.remove(valueOfElementToBeDeleted);
 
    // printing all the elements of the set
    System.out.print("Set after deleting " +
                     valueOfElementToBeDeleted +  ": ");
    printSet(myset);
  }
 
  // Driver code
  public static void main (String[] args)
  {
 
    //Set<Integer> myset = new HashSet<Integer>();
    TreeSet<Integer> myset = new TreeSet<Integer>();
 
    // Get the set
    for (int i = 1; i < 10; i++)
    {
      myset.add(i * 10);
    }
 
    // Get the valueOfElementToBeDeleted
    int valueOfElementToBeDeleted = 50;
 
    // Delete an element from the Set
    deleteByValue(myset, valueOfElementToBeDeleted);
  }
}
 
// This code is contributed by avanitrachhadiya2155

Python3

# Python3 program to delete an element of a
# set by passing of a set by passing its value
 
# function to print the set
def printset(myset):
     
    for i in myset:
        print(i, end = " ")
    print()
 
# function to delete the element of a set
def deleteByValue(myset, value):
     
    myset = sorted(myset)
     
    # printint original value
    print("Set orginally:", end = " ")
    printset(myset)
     
    # Erase the element that is equal to
    # the value passed as the parameter
    myset.remove(value)
     
    # printing all the elements of the set
    print("Set after deleting", value,
                        ":", end = " ")
    printset(myset)
 
# Driver code
myset = set()
 
for i in range(1, 10):
    myset.add(i * 10)
 
# Get the valueOfElementToBeDeleted
value = 50
 
# Delete an element from the Set
deleteByValue(myset, value);
 
# This code is contributed
# by Mohit kumar 29

C#

// C# program to delete an element
// of a Set by passing its value
using System;
using System.Collections.Generic;
public class GFG
{
 
  // Function to print the set
  static void printSet(HashSet<int> myset)
  {
 
    // printing all the elements of the set
    foreach(int it in myset)
    {
      Console.Write(it + " ");
    }
    Console.WriteLine();
  }
 
  // Function to delete the element of set
  static void deleteByValue(HashSet<int> myset, int valueOfElementToBeDeleted)
  {
 
    // printing all the elements of the set
    Console.Write("\nSet originally: ");
    printSet(myset);
 
    // Erase the element that is equal to
    // the value passed as the parameter
    myset.Remove(valueOfElementToBeDeleted);
 
    // printing all the elements of the set
    Console.Write("Set after deleting " + valueOfElementToBeDeleted +  ": ");
    printSet(myset);
  }
 
  // Driver code
  static public void Main ()
  {
    //Set<Integer> myset = new HashSet<Integer>();
    HashSet<int> myset = new HashSet<int>();
 
    // Get the set
    for (int i = 1; i < 10; i++)
    {
      myset.Add(i * 10);
    }
 
    // Get the valueOfElementToBeDeleted
    int valueOfElementToBeDeleted = 50;
 
    // Delete an element from the Set
    deleteByValue(myset, valueOfElementToBeDeleted);
  }
}
 
// This code is contributed by rag2127

Javascript

<script>
 
// JavaScript program to delete an element
// of a Set by passing its value
 
 // Function to print the set
function printSet(myset)
{
    // printing all the elements of the set
    for(let it of myset.values())
    {
      document.write(it + " ");
    }
    document.write("<br>");
}
 
 // Function to delete the element of set
function deleteByValue(myset, valueOfElementToBeDeleted)
{
    // printing all the elements of the set
    document.write("<br>Set originally: ");
    printSet(myset);
  
    // Erase the element that is equal to
    // the value passed as the parameter
    myset.delete(valueOfElementToBeDeleted);
  
    // printing all the elements of the set
    document.write("Set after deleting " +
                     valueOfElementToBeDeleted +  ": ");
    printSet(myset);
}
 
// Driver code
 
//Set<Integer> myset = new HashSet<Integer>();
    let myset = new Set();
  
    // Get the set
    for (let i = 1; i < 10; i++)
    {
      myset.add(i * 10);
    }
  
    // Get the valueOfElementToBeDeleted
    let valueOfElementToBeDeleted = 50;
  
    // Delete an element from the Set
    deleteByValue(myset, valueOfElementToBeDeleted);
 
 
// This code is contributed by patel2127
 
</script>

Output:

Set originally:  10 20 30 40 50 60 70 80 90
Set after deleting 50:  10 20 30 40 60 70 80 90

Want to learn from the best curated videos and practice problems, check out the C++ Foundation Course for Basic to Advanced C++ and C++ STL Course for foundation plus STL. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.

My Personal Notes

Related Articles

C++

Java

Python3

C#

Javascript