public Result GetMaxWordsRectangle(List <string> words)
{
Result result = null;
WordsMap wordsMap = new WordsMap(words);
int rowLength;
Indices currentIndices = new Indices();
Trie columnWords;
while (wordsMap.Get(currentIndices.RowLengthIndex, out rowLength, out columnWords))
{
Indices currentInnerIndices = new Indices();
currentInnerIndices.RowLengthIndex = currentIndices.RowLengthIndex;
int columnLength;
Trie rowWords;
while (wordsMap.Get(currentInnerIndices.ColumnLengthIndex, out columnLength, out rowWords))
{
WordsMatrix matrix = GetMaxWordsRectangle(wordsMap, rowWords, columnWords, rowLength, columnLength);
if (matrix != null)
{
//Return first result since we start with max length
return(new Result(matrix.Size, matrix.GetList()));
}
currentInnerIndices.IncrementColumn();
}
currentIndices.IncrementRow();
}
return(result);
}
void FillRowInRectangle(WordsMatrix wordsRectangle, WordsMatrix.Location row, WordsMatrix.Location column,
Trie rowWords, Trie columnWords, string rowWord)
{
if (wordsRectangle.IsFull)
{
return;
}
if (wordsRectangle.FillRow(row, rowWord))
{
// rectangle is full
string lastColumnWord = wordsRectangle.GetLastColumnWord();
if (columnWords.Contains(lastColumnWord))
{
wordsRectangle.FillColumn(column, lastColumnWord);
}
return;
}
var columnPrefix = wordsRectangle.GetColumnPrefix(column.Index);
foreach (string columnWord in columnWords.StartsWith(columnPrefix))
{
FillColumnInRectangle(wordsRectangle,
new WordsMatrix.Location(row), new WordsMatrix.Location(column), rowWords, columnWords, columnWord);
}
}
private WordsMatrix GetMaxWordsRectangle(WordsMap wordsMap, Trie rowWords, Trie columnWords, int rowLength, int columnLength)
{
foreach (string rowWord in rowWords)
{
WordsMatrix wordsRectangle = new WordsMatrix(rowLength, columnLength);
// Alternate betweem row and column to fill the rectangle
FillRowInRectangle(wordsRectangle, new WordsMatrix.Location(), new WordsMatrix.Location(),
rowWords, columnWords, rowWord);
// When returned from recursive calls check the last column
if (wordsRectangle.IsFull)
{
return(wordsRectangle);
}
}
return(null);
}
void FillColumnInRectangle(WordsMatrix wordsRectangle, WordsMatrix.Location row, WordsMatrix.Location column,
Trie rowWords, Trie columnWords, string columnWord)
{
if (wordsRectangle.IsFull)
{
return;
}
if (wordsRectangle.FillColumn(column, columnWord))
{
// Finished columns
return;
}
var rowPrefix = wordsRectangle.GetRowPrefix(row.Index);
foreach (string rowWord in rowWords.StartsWith(wordsRectangle.GetRowPrefix(row.Index)))
{
FillRowInRectangle(wordsRectangle,
new WordsMatrix.Location(row), new WordsMatrix.Location(column), rowWords, columnWords, rowWord);
}
}
