Working with deque

This C++ file utilizes the Standard Template Library (STL) to work with a `deque`, which stands for double-ended queue. Here's a breakdown of what the code does: 1. **Includes Required Headers**: It includes `iostream` for input and output operations and `deque` for using the `deque` container. 2. **Main Function**: The program starts execution in the `main` function. 3. **Deque Initialization**: A `deque` named `numbers` is created with an initial size of 5, which means it can hold up to 5 integers. 4. **Iterator Declaration**: An iterator `it` is declared for iterating through the `deque`. 5. **Input Loop**: A loop begins that runs through each element of the `deque` using the iterator. It prompts the user to enter a positive number. The user can enter numbers until they input -1, which breaks the loop. 6. **Storing Input**: If the user inputs a valid number (not -1), it assigns that number to the current position pointed by the iterator (`*it = temp`). 7. **Output Size**: After each valid input, it outputs the current size of the `deque`. This code allows the user to enter numbers into a `deque` and keeps track of the size after each input, stopping when they enter -1. Note that the program does not check whether the user exceeds the initial capacity of the `deque` or whether the values entered are indeed positive integers, which could be a potential enhancement in a more robust implementation.