This page should provide sufficient information to help you to decide if you want to try the program, and, if so, enough about the interface to enable you to get started. A more succinct summary of how to use the program is available in the Frequently asked questions (FAQ). However, should you want to do a complete read through, the easiest way is to use the arrows to the left and right of each page.
The first screen dump illustrates the interface and some of the program's features. It shows a partially completed grid. Above the grid is a row of menus and a toolbar. Below the grid are numbers describing the current state of play. The menus and toolbar give access to a range of options which can be employed to aid solving the puzzle. This includes automatic flagging of inconsistent or incorrect answers, quick filtering out of the possibilities for cells, facilities for colouring selected cells and specific candidates to help detect patterns, and hints from the application of several algorithms.
The large numbers in the grid are the solutions for the cells and the small numbers in each cell are the remaining candidates for each cell. These small numbers not only show the remaining possibilities, but are actually buttons which can be used to turn the symbols on and off. Hence the program can be used as a kind of notepad of the possibilities still remaining for each cell.
The state shown is one in which the user has clicked on the "?" button to ask for a hint and the program has shaded red 4 candidate 6s and also the "?" and "UC" buttons, indicating that the hint is for the UC method. The removal of candidates is achieved simply by clicking on them with the left mouse button. Alternatively, to set the solution for a cell the user clicks on the corresponding candidate with the right mouse button. This will set the large symbol in the centre of the cell and switch off all the small ones. If the user discovers that the solution for a cell has been set incorrectly, all nine symbols can be reactivated by clicking on the bottom right hand button ("R") in the cell. Note that the hint can also be executed by left clicking on the red buttons in the Toolbar. i.e. clicking on the Toolbar with the left mouse button will automatically remove all candidates shaded red by the hint. Conversely, the hint can be turned off by right clicking on the red buttons in the Toolbar. (The hint found is explained in the UC section, but the 6s can be removed because the second cell down does not contain any of the other candidates in the combination [1,2,3,5,6]).
Hints can be requested for specific "algorithms" by clicking on their symbol in the Toolbar. Alternatively, if the user clicks on the "?" option in the Toolbar the program will try all of its algorithms. Then, depending on the current search strategy it will either report the hint which removes the most candidates or the simplest hint.
Of course the hint options are only there if users gets stuck or to help beginners learn new techniques. Probably the most useful information to a Kakuro player is a list of the possible combinations for a given sum. These can be obtained from printed tables but a big advantage of SourGumdropK over using pencil and paper is that it displays the relevant combinations when the user clicks on the symbols which give the sum at the start of each row or column, AND IT KEEPS THEM UP TO DATE: every time a guess is set or unset for a row or column the possible combinations are reset.
The program has a set of built-in puzzles but puzzles can also be read from files or entered via a simple text editor window. Partially completed puzzles can be saved to files and subsequently reloaded for further struggles.
The puzzles are given a numerical difficulty rating depending on the algorithms required in their solution.
The areas in the centre of each cell which contain the symbols for the solved clues are also buttons. In this case, menu buttons, and they give access to options which can be applied to the individual cell, including showing the correct solution and colouring the cell to aid the search for patterns. A related option in the File menu allows the user to request that all symbols of a particular type, say all 2s, are set to a given colour, again to aid pattern recognition.
The program remembers every step made while a puzzle is being worked on. The user can go back one step at a time using the < button on the Toolbar, or can go back to the last consistent state with a single click on the << button
When doing a puzzles on paper and penciling in candidates we would usually only write down the candidates possible for each individual cell depending on the row and column sums. In SourGumdropK, when a new puzzle is loaded all 9 candidates are shown in each cell. The "S" and "SF" buttons in the Toolbar execute a simple filter, in which candidates which do not appear in any of each cells row and column combinations are removed. Also the symbols set in completed cells are turned off in all the unsolved cell's if they are in the same strip. "SF" does one step at a time and is subject to the hint mechanism, but "S" instantly performs as many such operations as are possible for the current state of the grid. Although purists may deprecate its use, "S" can save a lot of tedious mouse clicks and give the user more time to work on the interesting parts of problems.
The five numbers beneath the grid give the Puzzle Number, the number of steps taken by the User, the number of states recorded (History), the remaining Information content, of the puzzle (actually the total number of candidates left), and the time taken in seconds.