forward_list resize() function in C++ STL

The forward_list::resize() is an inbuilt function in C++ STL which changes the size of forward_list. If the given size is greater than the current size then new elements are inserted at the end of the forward_list. If the given size is smaller than current size then extra elements are destroyed. Syntax:

forwardlist_name.resize(n)

Parameter: The function accepts only one mandatory parameter n which specifies the new size of the forward list. Return value: The function does not return anything. Below programs illustrates the above function: 

Program 1:

CPP

// C++ program to illustrate the
// forward_list::resize() function
#include <bits/stdc++.h>
using namespace std;

int main()
{
    forward_list<int> fl = { 10, 20, 30, 40, 50 };

    // Prints the forward list elements
    cout << "The contents of forward list :";
    for (auto it = fl.begin(); it != fl.end(); ++it)
        cout << *it << " ";

    cout << endl;

    // resize to 7
    fl.resize(7);

    // // Prints the forward list elements after resize()
    cout << "The contents of forward list :";
    for (auto it = fl.begin(); it != fl.end(); ++it)
        cout << *it << " ";

    return 0;
}

Output:

The contents of forward list :10 20 30 40 50 
The contents of forward list :10 20 30 40 50 0 0

Program 2:

CPP

// C++ program to illustrate the
// forward_list::resize() function
#include <bits/stdc++.h>
using namespace std;

int main()
{
    forward_list<int> fl = { 10, 20, 30, 40, 50 };

    // Prints the forward list elements
    cout << "The contents of forward list :";
    for (auto it = fl.begin(); it != fl.end(); ++it)
        cout << *it << " ";

    cout << endl;

    // resize to 3
    fl.resize(3);

    // Prints the forward list elements after resize()
    cout << "The contents of forward list :";
    for (auto it = fl.begin(); it != fl.end(); ++it)
        cout << *it << " ";

    return 0;
}

Output:

The contents of forward list :10 20 30 40 50 
The contents of forward list :10 20 30

Time Complexity: O(n)

Auxiliary Space: O(1)