C++ multiset insert
The insert method in C++ Multiset is employed to add either a new element or a series of elements into the multiset data structure.
Syntax
single element (1) iterator insert (const value_type& val); //until C++ 11
with hint (2) iterator insert (iterator position, const value_type& val); //until C++ 11
range (3) template <class InputIterator>
void insert (InputIterator first, InputIterator last); //until C++ 11
single element (1) iterator insert (const value_type& val);
iterator insert (value_type&& val); //since C++ 11
with hint (2) iterator insert (const_iterator position, const value_type& val);
iterator insert (const_iterator position, value_type&& val); //since C++ 11
range (3) template <class InputIterator>
void insert (InputIterator first, InputIterator last); //since C++ 11
initializer list (4) void insert (initializer_list<value_type> il); //since C++ 11
Parameter
val: Value to insert in the multiset.
Hint for the optimal placement of an element within the multiset.
first: Beginning of range to insert value.
last: End of range to insert value.
il: An initializer list.
Return value
The insert method provides an iterator that points to the recently added element within the multiset.
Complexity
If a solitary element is added, the complexity will scale logarithmically based on the size.
If a clue is provided and the specified location is ideal, the complexity will be constant on average.
Iterator validity
No changes.
Data Races
The container is modified.
Simultaneously accessing the current elements within a multiset is considered secure, but iterating over ranges in the container is not recommended.
Exception Safety
This function does not throw exception.
Example 1
Let's explore an uncomplicated illustration of adding elements to a multiset:
#include <iostream>
#include <set>
using namespace std;
int main()
{
multiset<int> s;
s.insert(1);
s.insert(4);
s.insert(2);
s.insert(3);
s.insert(3);
cout << "The elements in multiset are: ";
for (auto it = s.begin(); it != s.end(); it++)
cout << *it << " ";
return 0;
}
Output:
The elements in multiset are: 1 2 3 3 4
In the previously mentioned example, it merely adds the element with the specified key.
Example 2
Let's explore a basic illustration demonstrating the insertion of an element at a specific position:
#include <iostream>
#include <set>
using namespace std;
int main()
{
multiset<int> s;
// Function to insert elements
// in the multiset container
auto itr = s.insert(s.begin(), 1);
// the time taken to insertion
// is very less as the correct
// position for insertion is given
itr = s.insert(itr, 4);
itr = s.insert(itr, 2);
itr = s.insert(itr, 4);
itr = s.insert(itr, 3);
cout << "The elements in multiset are: ";
for (auto it = s.begin(); it != s.end(); it++)
cout << *it << " ";
return 0;
}
Output:
The elements in multiset are: 1 2 3 4 4
In the example provided, elements are added at the specified location.
Example 3
Let's explore a straightforward illustration of transferring the elements from one multiset to another within a specified range:
#include <iostream>
# include<iostream>
# include<set>
using namespace std;
int main()
{
multiset<int> s1;
// Function to insert elements
// in the multiset container
s1.insert(1);
s1.insert(4);
s1.insert(2);
s1.insert(4);
s1.insert(3);
cout << "The elements in multiset1 are: ";
for (auto it = s1.begin(); it != s1.end(); it++)
cout << *it << " ";
multiset<int> s2;
// Function to insert one multiset to another
// all elements from where 3 is to end is
// inserted to multiset2
s2.insert(s1.find(3), s1.end());
cout << "\nThe elements in multiset2 are: ";
for (auto it = s2.begin(); it != s2.end(); it++)
cout << *it << " ";
return 0;
}
Output:
The elements in multiset1 are: 1 2 3 4 4
The elements in multiset2 are: 3 4 4
Example 4
Let's explore a straightforward example of inserting elements from the initializer list:
#include <iostream>
#include <set>
using namespace std;
int main(void) {
multiset<string> m = {"Java", "C++", "SQL"};
// Insert the elements from an initializer_list
m.insert({"C++", "Oracle"});
cout << "Multiset contains following elements" << endl;
for (auto it = m.begin(); it != m.end(); ++it)
cout << *it<< endl;
return 0;
}
Output:
Multiset contains following elements
C++
C++
Java
Oracle
SQL
In the aforementioned example, components are added from an initializer list.
