Can you simultaneously get user input while also running a function in C++ for a windows program without using GetAsyncKeyState or threading?

I have a project that I am working on using Dev-C++ as the IDE and Windows as the operating system. As the project is restricted in complexity due to size constraints and current knowledge, I would prefer to avoid using GetAsyncKeyState and threading unless there is a fairly simple (less than 10 lines) approach I could use.

My program currently displays text using the Text function using strings and outputting them to the console window. I want to implement a feature that would allow the user to press a key, and allow the text to print out without waiting for the function to read the entire string.

For example:

"Welcome to ..." [user presses space bar while the text is slowly being displayed character by character]

"Welcome to my program! This was developed by me!" [entire string is displayed]

Code:

void Text(string input)
{
    int x = 0;
    for(int i = 0; i <= 3; i++) //decides when to stop running based on number of strings
    {
        while (input[x] != '\0')
        {
            if(input[x] == '.' || input[x] == '!')
            {
                cout << input[x];
                Sleep(375);
                cout << " ";
                x++;
            }
            else if(input[x] == '*')
            {
                Sleep(375);
                cout << endl;
                x++;
            }
            else if(input[x] == '~')
            {
                Sleep(2000);
                system("CLS");
                x++;
            }
            else
            {
                cout << input[x];
                Sleep(75);
                x++;
            }
        }
    }
}