PC Sudoku Samurai + PC Kakuro
After PC Sudoku's success, selling more than half a million units, Planeta DeAgostini decided to make this sequel. This new game includes 4 game types; Sudoku Classic, Sudoku Samurai, Sudoku Killer (also known as Samunamupure) and Kakuro. You can also set up multiple grid sizes for Sudoku Classic and Kakuro.
synchrnzr had to work on this project during Legend of the Dragon's development, so we just worked on the algorithms and interface design. Whe shared the last task with José Luis Cebrián, Freak Frog's lead programmer, who worked on the UI, but also provided very valuable hints to improve the solving algorithms, and therefore the creation algorithms too.
Though the original PC Sudoku only used 9x9 and 6x6 boards, synchrnzr had still coded a general algorithm that would take board size and cell groups as a parameter, so Sudoku Classic needed little work. Difficulty quotient was also improved, taking care of all human solving techniques. This new difficulty quotient was even more accurate than the quotient used in PC Sudoku.
Sudoku Samurai mode was easy to do too, as it inherited many properties of the Sudoku Classic mode. However, it would the one with the slowest calculation, due to the huge board size. Sudoku Killer mode was a bit harder. Take a solution grid and start grouping cells is easy. However, grouping all cells and avoiding single ones is harder. Kakuro was something close to Sudoku Killer, but the implementation is way easier. The point here was to get beautiful boards with big board sizes, above 10 cells. You can't repeat a number on the same sum and you can use digits 1 to 9, so sums can't be longer than 9 cells. Each row and column have, at least, a black cell. Finding a good place for those cells, avoiding them to fall at the bottom of the board or grouping on the right proved to be a bit tricky.
The game was coded with Visual C++ using old Win32 GUI API like PC Sudoku, thus allowing it to run on old systems (Windows 98 and above)