What are some examples of using std::deque in C++?

Can you give me some examples of using std::deque in C++?

Sure! std::deque is a double-ended queue that allows insertion and deletion from both ends. Here's a simple example:

#include <iostream>
#include <deque>

int main() {
    std::deque<int> dq;
    dq.push_back(1); // Add to the back
    dq.push_front(2); // Add to the front
    dq.push_back(3);

    std::cout << "Deque elements: ";
    for (int n : dq) {
        std::cout << n << ' '; // Output: 2 1 3
    }
    return 0;
}

What are the advantages of using std::deque over std::vector?

std::deque offers several advantages over std::vector:

1. Efficient Insertions/Deletions: It allows fast insertions and deletions at both ends, while std::vector is slower for these operations.
2. Dynamic Size: std::deque can grow and shrink dynamically, similar to std::vector, but it manages memory differently, allowing for more efficient use in certain scenarios.
3. No Reallocation: Unlike std::vector, std::deque does not require reallocation when adding elements, which can lead to better performance in some cases.

Can you show me how to iterate through a std::deque?

Certainly! You can iterate through a std::deque using a range-based for loop or an iterator. Here's an example using both methods:

#include <iostream>
#include <deque>

int main() {
    std::deque<int> dq = {1, 2, 3, 4, 5};

    // Using range-based for loop
    std::cout << "Using range-based for loop: ";
    for (int n : dq) {
        std::cout << n << ' '; // Output: 1 2 3 4 5
    }

    // Using iterator
    std::cout << "\nUsing iterator: ";
    for (auto it = dq.begin(); it != dq.end(); ++it) {
        std::cout << *it << ' '; // Output: 1 2 3 4 5
    }
    return 0;
}