Mastersoft Kakuro -- Better than Sudoku?

About a year ago, I met Dom Masters of Mastersoft Mobile Solutions at a conference. He was very excited about the launch of their Pocket PC version of a new puzzle craze, Sudoku. He told me this logic puzzle was ideally suited for a pocket-sized computer. The challenge of the game is to fill in a 9 x 9 grid with the numbers 1 to 9 so that each column, row, and 3x3 box contains each number once and only once. Eventually, I tried it and Sudoku Rules by Spiral Miles I was hooked.

Since then, Sudoku has taken the world by storm. Entire sections of bookstores are devoted to Sudoku puzzles. There are so many software versions for the Pocket PC that we have added a new Sudoku category in our 2006 Best Software Awards www.pocketpcmag.com/awards

Several weeks ago, Dom E-mailed me, urging him to try Mastersoft Kakuro. He told me it was better and more addicting then Sudoku. I wasn’t sure that I wanted “more addicting” but I tried it anyway. Soon, again I was hooked. The nice thing is that Dom was able to adapt many of the powerful features of Mastersoft Soduku into Kakuro.

Just to give you an idea of how the game works, and a few of the features, I am going to take you through a “simple” game – the easiest out of six levels of difficulty. Here is the default opening screen. (Note you can apply skins to spruce up the look.)

The idea is to use numbers between 1 and 9, and make a sum of numbers equal to the total at the top of each column and left of each row, without using the same number twice. So for example, at the top right, the total must be 3. I therefore can quickly deduce that the numbers of the two cells in the right-most column must be 1 or 2. I can then deduce the top row, which totals 8, must contain a 6 or a 7. Similarly, the 2 cells in the bottom row, must be 7 or 9 (two 8’s aren’t allowed). Using entry tools it is easy to product a screen that looks like this:

The upper cell in the left-most column that totals 14, can only be a 5, since two 7’s aren’t allowed. Similarly, the center square has to be a 2, since no other number could work with the other two cells to total 15.

Now it is a simple matter of completing the puzzle by subtracting to determine missing number.

As the Kakuro puzzles get more advanced, the Mastersoft tools supplied are extremely clever and really help. My favorite is a pop-up manipulative-able matrix that shows you possibilities. For example, in the screen below of a new puzzle, I tapped 27. Up popped the matrix, which revealed the three ways 4 numbers between 1 and 9 could equal 27.

This shortcut matrix is invaluable in deducing solutions. Some of the other help methods include the ability to bookmark certain points in the deduction process, using different colors for tentative number solutions for a cell, and removal of content in cells by different criteria.

If you like logic puzzles, I recommend Mastersoft’s ingenious implementation of this game.