SourGumdrop

Have fun playing Sudoku with SourGumdrop and become an expert. Finish that puzzle that's got you stumped - just enter the clues and use SourGumdrop to guide you past the problem. Powerful but simple user interface. The user inteface minimises the effort required to work on puzzles and lets you concentrate on finding the solution. The solution for a single cell or the whole puzzle can be shown at any stage. You can colour cells and candidates to help identify patterns. Inconsistent or incorrect answers can be shown as you set them and all moves can be undone. Flexible hint methods: The hint methods can be configured to reveal carefully controlled amounts of information. Set them so you see only the minimum necessary to make progress, or use them to learn how to recognise patterns. Ask to highlight the candiates that can be removed, or the candidates that form the pattern, or ask to show only the cells involved in the pattern. Request the hint which is easiest to understand or the one which removes the most candidates. Hints can be requested for specific algorithms or for classes of algorithms. Hint algorithms: Hidden Singles, Hidden Pairs, Hidden Triples, Locked Candidates, Naked Pairs, Naked Triples, Naked Quads, Xwing, Swordfish and Jellyfish. Internal and external puzzles. SourGumdrop's built-in puzzles are given a difficulty rating depending on the algorithms required in their solution and puzzles can be selected based on their difficulty. Puzzles can be read from files or entered via a built-in editor. SourGumdrop can solve all puzzles. Entered puzzles are checked for internal consistency and for having a single solution. Partially completed puzzles can be saved to files along with their remaining candidates and then tried again later or sent to friends. The appearance of the program can be set using a configuration option and clues can be numerals or letters. The source code is included.