I heard Martin Gardner in one of his books presented a crossword, which looks like 3x3 square. Could you help me to find it?
Also, have been there a smaller crossword puzzle created?
I heard Martin Gardner in one of his books presented a crossword, which looks like 3x3 square. Could you help me to find it?
Also, have been there a smaller crossword puzzle created?
I found the book: M.Gardner "Aha. Insight.", p. 153.
Here is the crossword, which was called there "World's smallest crossword":
The clues are:
Horizontal: 1. Insect 4. To annoy 5. Eavesdropper
Vertical: 1. Stingers 2. To employ 3. Gigi has two
(There are typos in numbers 4 and 5).
Solution:
It's not hard to construct a 1x1 crossword:
+---+ |1 | | | +---+
Across:
- A Roman one.
Down:
- The shortest pronoun.
There's also a cheating one going around, with clues "What letter am I thinking of?" and "What is the answer to 1 Across?", and claimed solution "I'm thinking of U".
Here's a 3x3 crossword puzzle using only the first 5 letters of the alphabet:
Down
1. A flying one has downed his foes.
2. A taxi.
3. Decline, decay, or fade away.
Solution:
A C E
C A B
E B B
What a about the null crossword, presented below. It has no clues. This is the smallest crossword possible and yet impossible to solve. (Or not solve.)
George Perec actually jokingly designed a 1x1 grid, with the following clues:
Horizontalement : 1. Voyelle
Verticalement : 1. Consonne
see French Wikipedia.
In Italian, you may find a lot of examples in the site of Aldo Spinelli.
Across : 1. Vowel, Down : 1. Consonant
. Same solution works in English.
$\endgroup$
Commented
Mar 18, 2016 at 18:13
As Peter Taylor mentioned, it's possible to make a $1 \times 1$ crossword. Since crosswords don't necessarily have to use whole words in the English language like Scrabble does (abbreviations and proper nouns are totally fair game in crosswords), it's possible to use any of the $26$ letters in the single square, for a total of $26$ possible combinations.
If you get up to $2 \times 2$, there are four essentially distinct ways to block off squares that don't convert it into just a $1 \times 1$:
+---+---+ +---+---+ +---+---+ +---+---+
|1 |2 | |1 | | |1 |xxx| |1 |xxx|
| | | | | | | |xxx| | |xxx|
+---+---+ +---+---+ +---+---+ +---+---+
|3 | | | |xxx| | |xxx| |xxx|2 |
| | | | |xxx| | |xxx| |xxx| |
+---+---+ +---+---+ +---+---+ +---+---+
The last one, however, is just two $1 \times 1$s superimposed on a $2 \times 2$ board, which is uninteresting.
Each of these has multiple options for what words can go into them, which are hard to enumerate here.
If you are going by the rule that a crossword word must have at least three letters, the smallest grid you can make is $3 \times 3$, simply because a smaller grid can't fit a three-letter word into it. There are two ways such a grid can be made:
+---+---+---+ +---+---+---+
|1 |2 |3 | |1 | |2 |
| | | | | | | |
+---+---+---+ +---+---+---+
|4 | | | | |xxx| |
| | | | | |xxx| |
+---+---+---+ +---+---+---+
|5 | | | |3 | | |
| | | | | | | |
+---+---+---+ +---+---+---+
and again, a multitude of ways the letters can be filled in to make words.
The following is inspired by an old Swedish crossword puzzle, whose solution has the same structure.
Across: 1. Apex
Down: 2. Burden
+---+---+
|xxx|2 |
|xxx| |
+---+---+
|1 | |
| | |
+---+---+
Solution:
X W
H 8