How to deep Copy a List in C++ - Step by Step Examples

How to deep Copy a List in C++ ?

Answer

To deep copy a std::list in C++, you can use the list's copy constructor or the std::copy algorithm to create a new list with the same elements.

✐ Examples

1 Deep Copy a List of Integers

In this example,

We create a std::list named originalList with integer values.
We use the copy constructor of std::list to create a new list named deepCopiedList with the same elements.
Finally, we print both lists to verify the deep copy.

C++ Program

#include <iostream>
#include <list>

void printList(const std::list<int>& lst) {
    for (int val : lst) {
        std::cout << val << " ";
    }
    std::cout << std::endl;
}

int main() {
    std::list<int> originalList = {1, 2, 3, 4, 5};
    std::list<int> deepCopiedList = originalList;
    std::cout << "Original List: ";
    printList(originalList);
    std::cout << "Deep Copied List: ";
    printList(deepCopiedList);
    return 0;
}

Output

Original List: 1 2 3 4 5 
Deep Copied List: 1 2 3 4 5

2 Deep Copy a List of Custom Objects

In this example,

We define a class named Person with properties name and age.
We create a std::list named originalList containing Person objects.
We use the std::copy algorithm to iterate through each Person object and create a new list named deepCopiedList with the same elements.
Finally, we print both lists to verify the deep copy.

C++ Program

#include <iostream>
#include <list>
#include <algorithm>

class Person {
public:
    std::string name;
    int age;
    Person(std::string n, int a) : name(n), age(a) {}
    Person(const Person& other) : name(other.name), age(other.age) {}
    friend std::ostream& operator<<(std::ostream& os, const Person& p) {
        os << "Person(name: " << p.name << ", age: " << p.age << ")";
        return os;
    }
};

void printList(const std::list<Person>& lst) {
    for (const Person& p : lst) {
        std::cout << p << " ";
    }
    std::cout << std::endl;
}

int main() {
    std::list<Person> originalList = { Person("Alice", 30), Person("Bob", 25), Person("Charlie", 35) };
    std::list<Person> deepCopiedList;
    std::copy(originalList.begin(), originalList.end(), std::back_inserter(deepCopiedList));
    std::cout << "Original List: ";
    printList(originalList);
    std::cout << "Deep Copied List: ";
    printList(deepCopiedList);
    return 0;
}

Output

Original List: Person(name: Alice, age: 30) Person(name: Bob, age: 25) Person(name: Charlie, age: 35) 
Deep Copied List: Person(name: Alice, age: 30) Person(name: Bob, age: 25) Person(name: Charlie, age: 35)

Summary

In this tutorial, we learned How to deep Copy a List in C++ language with well detailed examples.

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How to deep Copy a List in C++ - Step by Step Examples

How to deep Copy a List in C++ ?

Answer

✐ Examples

1 Deep Copy a List of Integers

C++ Program

Output

2 Deep Copy a List of Custom Objects

C++ Program

Output

Summary

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