Demo of set::erase(), empty() , insert()

playSet.cpp

#include<iostream>
#include<set>
using namespace std;

int main(){
    set<char>mySet;
    for(char ch='a';ch<='z';ch++){
        mySet.insert(ch);
    }
    //display
while(!mySet.empty()){
     for(auto it=mySet.begin();it!=mySet.end();it++){
        cout<<*it<<" ";
    }

    char del;
        cout<<"Delete: ";
        cin>>del;
        mySet.erase(del);
    }

}