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Creating a crossword generator

, 15 Feb 2013
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Creating an application that can generate crosswords from a list of words

Download source code 

Introduction 

This article describes a simple application that can place a list of words, in either right-to-left or left-to-right language in a matrix, as a crossword.


Background 

A crossword is a word puzzle created from a grid of white and black squares, placing words horizontally and vertically on these squares while each two words which cross each other require having an identical letter at the place they are crossed.

The application described and included in this article is useful whenever there is a need to create a mechanism which will place words as a crossword, which would be the first step before composing clues and questions in which their answers will forms these words.

The Application

While designing this application, there were several guidelines to comply with:

Supporting right-to-left languages, such as Hebrew. To comply with this requirements words in such language goes from right to left, when placed horizontally, and still, from top to bottom when placed vertically. Latin words are place left to right, and from top to bottom.

Minimal distance between words placed at the same dimension. Two words placed horizontally or vertically one after the other will have at least one black square separating between the two.

An optimization process, used to find the optimal arrangement of any given set of words, which leave a minimum number of black square.

Loading words from a file, or placing them manually. The file should be an ASCII one, with one word per line.

The Code

The demo source code was created using c# and Visual Studio 2010. 

There are several building blocks: 

First, per each word about to be placed, we check if this place is valid :

bool IsValidPosition(int x , int y)
{  
     return x >= 0 && y >= 0 && x < _n && y < _m;
}   

Even if the position is valid, we also check if there is no other word crossing the word we are about to place, and if there is, the crossing point must have the same letter, both for the word placed horizontally and the word placed vertically.

int CanBePlaced(string word, int x, int y, int dir)
{
            var result = 0;
            if (dir == 0)
            {
                for (var j = 0; j < word.Length; j++)
                {
                    int x1 = x, y1 = y + j;
                    if (!(IsValidPosition(x1, y1) && (_board[x1, y1] == ' ' || _board[x1, y1] =                    = word[j])))
                        return -1;
                    if (IsValidPosition(x1 - 1, y1))
                        if (_hWords[x1 - 1, y1] > 0)
                            return -1;
                    if (IsValidPosition(x1 + 1, y1))
                        if (_hWords[x1 + 1, y1] > 0)
                            return -1;
                    if (_board[x1, y1] == word[j])
                        result++;
                }
            }
            else
            {
                for (var j = 0; j < word.Length; j++)
                {
                    int x1 = x + j, y1 = y;
                    if (!(IsValidPosition(x1, y1) && (_board[x1, y1] == ' ' || _board[x1, y1] =                    = word[j])))
                        return -1;
                    if (IsValidPosition(x1, y1 - 1))
                        if (_vWords[x1, y1 - 1] > 0)
                            return -1;
                    if (IsValidPosition(x1, y1 + 1))
                        if (_vWords[x1, y1 + 1] > 0)
                            return -1;
                    if (_board[x1, y1] == word[j])
                        result++;
                }
            }
            int xStar = x - _dirX[dir], yStar = y - _dirY[dir];
            if (IsValidPosition(xStar, yStar))
                if (!(_board[xStar, yStar] == ' ' || _board[xStar, yStar] == '*'))
                    return -1;
            xStar = x + _dirX[dir]*word.Length;
            yStar = y + _dirY[dir]*word.Length;
            if (IsValidPosition(xStar, yStar))
                if (!(_board[xStar, yStar] == ' ' || _board[xStar, yStar] == '*'))
                    return -1;
            return result == word.Length ? -1 : result;
        }
 

Then, when we actually place the word, we call: 

void PutWord(string word , int x , int y , int dir, int value)
{
    var mat = dir==0 ? _hWords :_vWords;
    for (var i = 0; i < word.Length; i++)
    {
        int x1 = x + _dirX[dir]*i, y1 = y + _dirY[dir]*i;
        _board[x1, y1] = word[i];
        mat[x1, y1] = value;
    }
    int xStar = x - _dirX[dir], yStar = y - _dirY[dir];
    if (IsValidPosition(xStar, yStar)) _board[xStar, yStar] = '*';
    xStar = x + _dirX[dir]*word.Length;
    yStar = y + _dirY[dir]*word.Length;
    if (IsValidPosition(xStar, yStar)) _board[xStar, yStar] = '*';
}

This application is meant only for demonstration purposes.  It creates a matrix of 13 X 17. The "Optimize" button, tries to place the list of given words randomly while seeking for the optimal result for up to 1 minute. Obviously, this is not optimizing, and there can be many improvements, which will be more than welcomed. 

 Michael Haephrati CodeProject MVP 2013   

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Michael N. Haephrati
CEO
United States United States
Michael Haephrati, born in 1964, an entrepreneur, inventor and a musician. Haephrati worked on many ventures starting from HarmonySoft, designing Rashumon, the first Graphical Multi-lingual word processor for Amiga computer.
 
Worked with Amdocs and managed several software projects, among them one for the Ministry of Tourism in New Zealand.  During 1995-1996 he worked as a Contractor with Apple at Cupertino. After returning to Israel, worked as a Project Manager with Top Image Systems (mostly with JCC, Nicosia), and then at a research institute made the fist steps developing the credit scoring field in Israel. He founded Target Scoring and developed a credit scoring system named ThiS, based on geographical statistical data, participating VISA CAL, Isracard, Bank Leumi and Bank Discount (Target Scoring, being the VP Business Development of a large Israeli institute).

During 2000, he founded Target Eye, and developed the first remote PC surveillance and monitoring system, named Target Eye.

Other ventures included: Data Cleansing (as part of the DataTune system which was implemented in many organizations.
 

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Comments and Discussions

 
GeneralMy vote of 5 PinmemberVitorHugoGarcia17-Jul-13 22:03 
GeneralMy vote of 5 Pingroupalonbarak14-Jun-13 11:10 
GeneralMy vote of 5 PinmemberMember 416352421-Feb-13 5:37 
GeneralMy vote of 5 PinmemberMihai MOGA16-Feb-13 19:16 
GeneralMy vote of 5 PinmemberBoipelo16-Feb-13 5:52 
QuestionCool Pinmember i0015-Feb-13 3:19 
AnswerRe: Cool Pinmember i0029-Apr-13 18:25 
GeneralMy vote of 5 PinmemberSavalia Manoj M14-Feb-13 14:44 
GeneralMy vote of 5 Pinmemberkhanhamid92211-Feb-13 4:07 
GeneralMy vote of 5 Pinmemberrumilal11-Feb-13 3:58 
GeneralGreat PinmemberAnand Gunasekaran8-Feb-13 21:55 
GeneralMy vote of 5 PinmemberMonjurul Habib2-Feb-13 7:04 
GeneralMy vote of 5 Pingroupbalam198824-Jan-13 22:25 
GeneralRe: My vote of 5 PinmvpMichael Haephrati מיכאל האפרתי24-Jan-13 22:41 
GeneralMy vote of 5 Pingroupevan89724-Jan-13 21:46 
GeneralMy vote of 5 PinmemberRutuanie24-Jan-13 19:32 
GeneralMy vote of 5 PinmemberEdo Tzumer23-Jan-13 2:14 
GeneralGood Article PinmemberAzziet23-Jan-13 1:21 
GeneralMy vote of 3 PinmemberAzziet23-Jan-13 1:20 
GeneralMy vote of 5 PinmemberSanjay_00722-Jan-13 22:52 
QuestionVery cool! PinmemberFrosty721-Jan-13 9:29 
GeneralMy vote of 5 Pinmemberkentclark51920-Jan-13 4:54 
very interesting
GeneralRe: My vote of 5 PinmvpMichael Haephrati מיכאל האפרתי20-Jan-13 5:13 
GeneralMy vote of 5 Pinmemberfaruk19683020-Jan-13 1:59 
GeneralMy vote of 5 Pinmembersrinivasreddypg19-Jan-13 22:04 
GeneralMy vote of 5 Pingroupnayeemsazzad19-Jan-13 21:52 
GeneralMy vote of 5 Pingrouparif111114219-Jan-13 21:41 
GeneralMy vote of 5 PinmemberJohn Klinner19-Jan-13 21:13 
GeneralMy vote of 5 Pingroupevan89719-Jan-13 10:39 

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