C++ set max_size
The max_size function in C++ is utilized to determine the maximum capacity that a set container can accommodate.
Syntax
The size_type member type is an unsigned integral data type.
size_type max_size() const; // until C++ 11
size_type max_size() const noexcept; //since C++ 11
Parameter
Return value
It provides the maximum permissible size of the set container.
Complexity
Constant.
Iterator validity
No changes.
Data Races
The container is accessed.
Simultaneously retrieving the elements of a set is considered secure.
Exception Safety
This member function never throws exception.
Example 1
Let's explore a straightforward example to determine the maximum size of a set:
#include <iostream>
#include <set>
using namespace std;
int main()
{
set<char,char> s;
cout << "Maximum size of a 'set' is " << s.max_size() << "\n";
return 0;
}
Output:
Maximum size of a 'set' is 461168601842738790
In the previous example, the max_size method retrieves the largest size of the set.
Example 2
Let's see a simple example:
#include <iostream>
#include <set>
using namespace std;
int main ()
{
int i;
set<int> myset;
if (myset.max_size()>1000)
{
for (i=0; i<1000; i++) myset.insert(0);
cout << "The set contains 1000 elements.\n";
}
else cout << "The set could not hold 1000 elements.\n";
return 0;
}
Output:
The set contains 1000 elements.
In the provided example, the member max_size is utilized to verify in advance if the set can accommodate the insertion of 1000 elements.
Example 3
Let's explore a basic illustration to determine the maximum size of a vacant set and a populated set:
#include <set>
#include <iostream>
using namespace std;
int main()
{
// initialize container
set<int> mp1, mp2;
mp1 = {1111};
// max size of Non-empty set
cout << "The max size of mp1 is " << mp1.max_size();
// max size of Empty-set
cout << "\nThe max size of mp2 is " << mp2.max_size();
return 0;
}
Output:
The max size of mp1 is 461168601842738790
The max size of mp2 is 461168601842738790
In the example provided, there are two collections known as m1 and m2. The set m1 contains elements, while set m2 is devoid of any elements. Despite this distinction, both sets have an equivalent maximum capacity.
Example 4
Let's see a simple example:
#include <iostream>
#include <set>
#include <string>
using namespace std;
int main() {
typedef set<string> city;
string name;
city fmly ;
int n;
cout<<"Enter the number of family members :";
cin>>n;
cout<<"Enter the name of each member: \n";
for(int i =0; i<n; i++)
{
cin>> name; // Get key
fmly.insert(name); // Put them in set
}
cout<<"\nTotal number of population of city set: "<<fmly.max_size();
cout<<"\nTotal member of family is:"<< fmly.size();
cout<<"\nName of family members: \n";
cout<<"\nName \n ________________________\n";
city::iterator p;
for(p = fmly.begin(); p!=fmly.end(); p++)
{
cout<<(*p)<<" \n ";
}
return 0;
}
Output:
Enter the number of family members: 5
Enter the name of each member:
Aman
Nikita
Divya
Amita
Kashish
Total number of population of city set: 461168601842738790
Total member of family is:5
Name of family members:
Name
________________________
Aman
Amita
Divya
Kashish
Nikita
In the previous example, the software initially generates a city set interactively with a specified size. Subsequently, it showcases the maximum capacity of a city set, the total size of a family, and the complete list of names along with their corresponding ages stored within the set.
