I want to make a game (something like theses) in C++ (Visual C++). Now a graphic game needs to refresh its picture quite often. How do I do that in command line? The only way I know is to print around 20 blank lines. This method is unefficient and quite "laggy". What I need is something fast and efficient and that cause no memory problem because the game will process a lot of data (like mouvements, scores, coins...).
The command line has no image output. The only way you can fake it on the command line is the way you have described it.
The way to make a game efficient is to create a window yourself and then draw with DirectX or OpenGL something into that window. Then you can clear it and redraw it. This might not satisfy you at the moment, as it sounds more like a quick project. But in the long run, you will not be happy to "draw" on the command line if you search for efficiency.