Bacarba
If you love the idea of Su Doku but hate dealing with numbers, Bacarba is most definitely for you. But how can a puzzle involving just three letters be so excruciatingly addictive? Maybe it's because the concept is easier than A, B, C.
How to...
The idea is to place the letters A, B, C, in the grid so that each letter appears once and only once in every row and every column. The letters lurking outside the grid represent the first letter seen as you look down that row or column. Get it? Got it? Good!
Like many grid-based brainteasers, the trick with Bacarba is to constantly cross reference in order to work out where each letter goes. When looking around the edges of the puzzle, keep an eye out for any letter that appears just once in a column or row of outside letters. This tells you that letter has to go in the first square in that row/column.
To enter a letter click in the box and type. If you make a mistake simply click in the box and delete or hit the reset button.
Example 1
We know that the square in the top left corner must stay blank because of the C at the top and the A at the side. Think about it: C has to be the first letter reading down and A has to be the first letter reading across, so neither can go in that first square. Consequently it stays empty. Still with us?
As C only appears once in the column on the side, this must be the square that it sits in on the first column. And if this is correct, both squares above must also be blank.
Example 2
Now we can do the same thing from the bottom up. Because we know the bottom left corner must stay blank, we now have all three blanks for this column in place. This means we need a letter in each of the remaining squares. Remember, these blanks must be the letters stated outside the grid so that they are the first in those rows.
The idea is to work around all the edges of the grid using this method until you arrive at a situation like the one shown in Example 3.
Example 3
Take a look at the third column in this example. The top and bottom letters have already been filled in. That means we only need to work out where the third letter (B) goes. On the third row down the letter A has already been filled in. We know the letters have to follow the order A C B because there is no empty square between the A and the highlighted square in which to place the C. Therefore this square must be blank. You can now fill in the rest of this row (C then B) as there are only two empty squares left.
