TheDeveloperBlog.com

Home | Contact Us

C-Sharp | Java | Python | Swift | GO | WPF | Ruby | Scala | F# | JavaScript | SQL | PHP | Angular | HTML

C++ multiset crend() function

C++ multiset crend() Function with Examples on tutorial for beginners and professionals with examples on multiset, begin(), end(), multiset constructor, ~multiset destructor, operator=, rbegin(), rend() etc.

<< Back to CPP

C++ multiset crend()

C++ multiset crend() function is used to return a constant iterator to the end of the multiset (not the last element but the past last element) in reverse order. This is similar to the element preceding the first element of the non-reversed container.

Note:- This is a placeholder. No element exists in this location and attempting to access is undefined behavior.

A constant iterator is an iterator that points to the constant content.

Syntax

const_reverse_iterator crend() const noexcept;       //since C++ 11

Parameter

None

Return value

crend() funtion returns a const_reverse_iterator to the element following the last element of the reversed container.

Complexity

Constant.

Iterator validity

No changes.

Data Races

The container is accessed.

Concurrently accessing the elements of a multiset container is safe.

Exception Safety

This function never throws exception.

Example 1

Let's see the simple example for crend() function:

#include <iostream>
#include <set>

using namespace std;

int main ()
{
  multiset<int> mymultiset = {40,20,30,10,20};

  cout << "mymultiset in reverse order:";
  for (auto rit=mymultiset.crbegin(); rit != mymultiset.crend(); ++rit)
    cout << ' ' << *rit;

  cout << '\n';

  return 0;
}

Output:

mymultiset in reverse order: 40 30 20 20 10

In the above example, crend() function is used to return a constant reverse iterator to the element following the last element of the reversed container.

Because multiset stores the elements in sorted order of keys therefore, iterating over a multiset will result in above order i.e. sorted order of keys.

Example 2

Let's see a simple example to iterate over the multiset in reverse order using while loop:

#include <iostream>
#include <set>
#include <string>
#include <iterator>

using namespace std;
 
int main() {
 
	// Creating & Initializing a multiset of String & Ints
	multiset<string> multisetEx = {"ccc", "bbb", "aaa", "bbb"};
 
	// Create a multiset iterator and point to the end of multiset
	multiset<string>::const_reverse_iterator it = multisetEx.crbegin();
 
	// Iterate over the multiset using Iterator till beginning.
	while (it != multisetEx.crend()) {
		// Accessing KEY from element pointed by it.
		string word = *it;
 
		cout << word << endl;
 
		// Increment the Iterator to point to next entry
		it++;
	}
	return 0;
}

Output:

ccc
bbb
bbb
aaa

In the above example, we are using while loop to const_iterate over the multiset in reverse order.

Because multiset stores the elements in sorted order of keys therefore, iterating over a multiset will result in above order i.e. sorted order of keys.

Example 3

Let's see a simple example:

#include <iostream>
#include <set>
#include <algorithm>

using namespace std;

int main()
{
  multiset<int> c = {3, 1, 2, 2};

  for_each(c.crbegin(), c.crend(), [](const int& x) {
    cout << x << endl;
  });
}

Output:

3
2
2
1

In the above example, elements of multiset returned in reverse order.

Example 4

Let's see a simple example to sort and calculate the highest marks:

#include <iostream>
#include <string>
#include <set>

using namespace std;

int main ()
{
  multiset<int> emp = {1000,2500,4500,1200,2500};

   cout << "Salary"<< '\n';
   cout<<"______________________\n";
   
  multiset<int>::const_reverse_iterator rit;
  for (rit=emp.crbegin(); rit!=emp.crend(); ++rit)
    cout << *rit<< '\n';

    auto ite = emp.crbegin();
 
    cout << "\nHighest salary: "<< *ite <<" \n";

  return 0;
  }

Output:

Salary
______________________
4500
2500
2500
1200
1000

Highest salary: 4500

In the above example, a multiset emp is implemented where salary is stored as key. This enables us to take advantage of the auto sorting of salary in multiset and lets us to identify the highest salary.

Next TopicC++ multiset




Related Links:

.Net

.NET Array Dictionary List String 2D Async DataTable Dates DateTime Enum File For Foreach Format IEnumerable If IndexOf Lambda LINQ Parse Path Process Property Regex Replace Sort Split Static StringBuilder Substring Switch Tuple

Java

Core Array ArrayList HashMap String 2D Cast Character Console Deque Duplicates File For Format HashSet If IndexOf Lambda Math ParseInt Process Random Regex Replace Sort Split StringBuilder Substring Switch Vector While

Related Links

Adjectives Ado Ai Android Angular Antonyms Apache Articles Asp Autocad Automata Aws Azure Basic Binary Bitcoin Blockchain C Cassandra Change Coa Computer Control Cpp Create Creating C-Sharp Cyber Daa Data Dbms Deletion Devops Difference Discrete Es6 Ethical Examples Features Firebase Flutter Fs Git Go Hbase History Hive Hiveql How Html Idioms Insertion Installing Ios Java Joomla Js Kafka Kali Laravel Logical Machine Matlab Matrix Mongodb Mysql One Opencv Oracle Ordering Os Pandas Php Pig Pl Postgresql Powershell Prepositions Program Python React Ruby Scala Selecting Selenium Sentence Seo Sharepoint Software Spellings Spotting Spring Sql Sqlite Sqoop Svn Swift Synonyms Talend Testng Types Uml Unity Vbnet Verbal Webdriver What Wpf