Removing from a Set and Looping Over It in C#

HashSet<string> colors = new HashSet<string>(new[] {"red", "blue", "green"});

colors.Remove("blue");

colors.Remove("pink");          // not in it, nothing happens

foreach (string color in colors) {
    Console.WriteLine(color);   // red and green, in any order
}

Full lesson:

s.Remove(x) removes x from the set s. It returns true if x was there. If it wasn't, nothing happens and it returns false.

foreach (string x in s) visits each value of the set once. The order isn't fixed. It may differ from the order you added the values in.

So loop over a set when the order doesn't matter. A total, a count and a check are fine.

Be careful when you change a set inside a loop over it. Removing a value there works in C#. Adding one stops the program with an InvalidOperationException. The safe habit: remove first, then loop.

Your task

In a word game, the set found holds the words a player found. The words "qqq" and "zzz" aren't allowed. Remove both from found.

The player never found "zzz", so removing it changes nothing.

Then add up the points. A word scores one point per letter. Loop over found and add each word's length to score.

The code already prints how many words are left, and the points.

Expected output:

4 words
14 points