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Converting String into Set in C++ STL

C++ STL | Converting String into Set: Here, we are going to learn how to convert String into Set in C++ Standard Template Library (STL)?
Submitted by Sanjeev, on April 16, 2019

C++ STL (Standard Template Library) supports multiple templates which we can use to perform different functions.

What are sets in C++ STL?

Sets are one of the templates available in the C++ STL. Sets are the containers which stores unique elements i.e. one element can occur only once.

Converting String into Set in C++ STL

Strings can be converted into sets by any one of the following methods.

1) By passing string into the set constructor

set <char>set_obj ( begin( string_name ) , end( string_name ) )

2) By iterating over the string using for-each loop

for ( auto  x : string_name )
    set_obj.insert( x )

By using the above two methods, a string can be converted into a set.

C++ STL program to convert string into set

#include <bits/stdc++.h>

// To use sets and set related functions
#include <set>

// To use strings and string related functions
#include <string>
using namespace std;

int main(){

    string name = "Includehelp";

    // Method 1, by passing string into the set constructor;
    set <char> set_name(begin(name), end(name));

    cout << "Converted by passing string into constructor" << endl;

    // Range-based for loop OR For-each loop
    for (auto i : set_name)
        cout << i << " ";
    cout << endl;

    // Method 2, by iterating over string and inserting each
    // element of string into the set
    set <char> name_set;

    // Ranged-based for loop OR For-each loop
    for (auto i : name)
        name_set.insert(i);

    cout << "Converted by iterating over string" << endl;

    // Range-based for loop OR For-each loop
    for (auto i : name_set)
        cout << i << " ";
    cout << endl;

    return 0;
}

Output

Converted by passing string into constructor
I c d e h l n p u
Converted by iterating over string
I c d e h l n p u