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C++ Forward List

This quiz tests your knowledge of C++ Forward List container and its associated operations. It contains 10 MCQs.

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Question 1

What is the missing line of code in this code to print maximum of two numbers?

C++

#include <bits/stdc++.h>
using namespace std;
int main()
{
    list<int> l = {1, 2, 3, 4};
    auto it = l.front();
    it++;
    cout << *(it);
}

Compilation error
Undefined behaviour
2
1

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Question 2

Predict the output of the following code:

C++

#include <bits/stdc++.h>
using namespace std;
class A
{
  public:
    int x, y;
    A(int a, int b) : x(a), y(b)
    {
    }
};

int main()
{
    forward_list<A> fl = {{1, 2}};
    fl.insert_after(fl.begin(), {3, 4});
    auto it = ++fl.begin();
    cout << it->x << " " << it->y;
    return 0;
}

Compiler Error
3 4
1 2
0 0

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Question 3

What is the result of l.unique() for list<int> l = {1, 1, 2, 3, 3};?

{1, 2, 3}
{1, 1, 2, 3, 3}
{1, 2, 3, 3}
Compilation error

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Question 4

Which code reverses a forward_list?

reverse(fl.begin(), fl.end());
Neither
fl.reverse();
Both (a and c)

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Question 5

Which code compiles without errors?

forward_list<int> fl;
fl.push_back(10);
forward_list<int> fl;
fl.erase(fl.begin());
list<int> l;
l.erase_after(l.begin());
list<int> l;
l.push_front(10);

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Question 6

What is the output of this program?

C++

#include <forward_list>
#include <iostream>
using namespace std;
int main()
{
    forward_list<int> fl = {1, 2, 3};
    fl.erase_after(fl.begin());
    cout << *(++fl.begin());
    return 0;
}

3
2
1
Undefined behavior

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Question 7

What happens if you call pop_back() on a forward_list?

Removes the last element
Undefined behavior
Runtime error
Compilation error

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Question 8

Which function merges two sorted lists into one sorted list?

merge()
join()
combine()
concat()

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Question 9

What will the following code print?

C++

#include <forward_list>
#include <iostream>
using namespace std;
int main()
{
    forward_list<int> flist = {1, 2, 3};
    flist.push_front(0);
    std::cout << flist.front();
    return 0;
}

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Question 10

What is the underlying data structure of std::forward_list?

Doubly-linked list
Singly-linked list
Dynamic array
Balanced tree

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C++

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