main() it’s the first function that system runs when a c++ application it’s executed.
In this code we see that the application runs as a cmd/terminal application. This is because the ‘std’ I/O library functionality it’s called multiple times in this function. The first line calls it and it clears the terminal, in other words clears all the cmd lines written, in order to let the application starts at the terminal’s first line in case you’d been using it before starts this application.
The main function then declares two ‘int’ variables that stores the value of the difficulty of this game. Difficulty starts at 2 and the max difficulty will be 10.
While difficulty it’s lower than 10 a code block is executed. At the first time this function is executed difficulty it’s 2 so the code inside it’s executed. This code executes a function named PlayGameAtDifficulty that needs the difficulty parameter. This function code isn’t shown at us so we are going to suppose that executes the core of the game at a given difficulty.
When PlayGameAtDifficulty function returns the control to main function there are two std library function executed that cleans the buffer of the user’s cmd/terminal entry (cin). This prevents that the previous usage of ‘cin’ stores stuff that we don’t want at the application buffer. In main we don’t see an usage of this user input so we can suppose that PlayGameAtDifficulty function is using it. This can be just a preventive technique. We can discuss if these ‘cin’ management functions should be executed here or at the end of PlayGameAtDifficulty because IMO a function mustn’t take responsibility of other functionality that it’s called inside. In case that this is a preventive technique then it’s all right.
No matter where the user input management function are executed difficulty increases and while block of code executes again until the difficulty arrives to max and the user wins the game.
At the end a message to the user is sent with the cout functionality explaining that he has win and the game closes with the return command that indicates that everything goes well.
For each level of difficulty, the function PlayGameAtDifficulty is called and once the level is played, it goes to the next level anyway…? Game does not end if user ends wrong combination…? In any case, it clears input buffer too before calling the function again.