Extra Regex Examples

Example #1

In the first example, we've gotten very lucky and have quickly narrowed down the possibilities.

a) Green Letters

By the second line, we've already managed to confirm three letters. Let's go ahead and enter that into our tool. In accept only matches mode, we can put in the regex ide$ or ..ide to accept only words that end with those three letters.

b) Grey Letters

Next we will switch to remove matches mode and remove all the words which have any of the grey letters with this regex: [auosl].

c) Results

That leaves only these possibilities: bride, chide, gride, imide, pride, tride As you can see, we have rapidly narrowed the field, and only a few viable options remain.

Example #2

In this example we have less information available.

a) Green Letters

Our first regex will be similar to the first example, confirming the position of the S in this case.

^s in accept only matches mode means that all the words will start with an S.

b) Grey Letters

Likewise, we'll next remove the grey letters.

In remove matches mode, we'll enter [adiolide].

Note that we have repeated i and d twice each in the regex, but this is not a problem. Repeating the same letter multiple times in a character class has no effect.

c) Yellow Letters

There is one more piece of information that we can use to filter, which is U from the first line.

We know that there must be a U, and that it must not be in the second position.

We will start with the most simple one:
The regex u will match words which have a u, and will not match those that don't. The correct mode is accept only matches.

For the position of the U, there are several valid options. A few will be presented below:

• ^.u remove matches → Remove words where a u follows the first character.
• .[^u]... accept only matches → This option relies on the knowledge that all the words have 5 letters. [^u] is a negated character class, and means "any character except 'u'".
• u..$|u.$|u$ accept only matches → This option is more verbose, but uses | to define options of where the u could be. This option could replace the earlier u regex as well. It reads as "accept words that have a u in one of the last three positions".
• u.{0,2}$ accept only matches → This option is more succinct than the previous one, but otherwise equivalent.

d) Results

And finally, here are the remaining words, once we've used all of the information available:

Example #3

In this example, we have not managed to confirm the position of any letters at all.

a) Grey Letters

First things first, eliminate the grey letters from consideration.

• [audosde] → remove matches

b) Yellow Letters

There are several viable strategies for dealing with the yellow letters. Only one will be laid out here.

The first step will be to simply mark the letters as required.

• i accept only matches
• l accept only matches

Next we will constrain the positions of the letters.

• ^.l remove matches → Remove any word that has an l in the second position.
• i..?$ remove matches → Remove any word that ends with 1 or 2 characters preceded by an i.

c) Results