The multiset::clear() function is a built-in function in C++ STL which removes all elements from the multiset container. The final size of multiset container after removal is 0.
Syntax:
multiset_name.clear()
Parameters: The function does not accept any parameter.
Return Value: The function does not returns anything.
Below programs illustrates the multiset::clear() function:
Program 1:
// C++ program to demonstrate the // multiset::clear() function #include <bits/stdc++.h> using namespace std;
int main()
{ int arr[] = { 15, 10, 15, 11, 10 };
// initializes the set from an array
multiset< int > s(arr, arr + 5);
// prints all elements in set
cout << "The elements in multiset are: " ;
for ( auto it = s.begin(); it != s.end(); it++)
cout << *it << " " ;
cout << "\nThe size after clear() is: " ;
// erases all elements
s.clear();
cout << s.size();
return 0;
} |
The elements in multiset are: 10 10 11 15 15 The size after clear() is: 0
Time Complexity: O(N), where N is the total number of elements present in the multiset.
Auxiliary Space: O(N)
Program 2:
// C++ program to demonstrate the // multiset::clear() function #include <bits/stdc++.h> using namespace std;
int main()
{ int arr[] = { 15, 10, 15, 11, 10, 18, 18, 20, 20 };
// initializes the set from an array
multiset< int > s(arr, arr + 9);
// prints all elements in set
cout << "The elements in multiset are: " ;
for ( auto it = s.begin(); it != s.end(); it++)
cout << *it << " " ;
cout << "\nThe size after clear() is: " ;
// erases all elements
s.clear();
cout << s.size();
return 0;
} |
The elements in multiset are: 10 10 11 15 15 18 18 20 20 The size after clear() is: 0
Time Complexity: O(N), where N is the total number of elements present in the multiset.
Auxiliary Space: O(N)