void GermanStemmer::strip(StringBuffer& buffer)
{
bool doMore = true;
while ( doMore && buffer.length() > 3 ) {
if ( ( buffer.length() + substCount > 5 ) &&
buffer.substringEquals( buffer.length() - 2, buffer.length(), _T("nd"), 2 ) )
{
buffer.deleteChars( buffer.length() - 2, buffer.length() );
}
else if ( ( buffer.length() + substCount > 4 ) &&
buffer.substringEquals( buffer.length() - 2, buffer.length(), _T("em"), 2 ) ) {
buffer.deleteChars( buffer.length() - 2, buffer.length() );
}
else if ( ( buffer.length() + substCount > 4 ) &&
buffer.substringEquals( buffer.length() - 2, buffer.length(), _T("er"), 2 ) ) {
buffer.deleteChars( buffer.length() - 2, buffer.length() );
}
else if ( buffer.charAt( buffer.length() - 1 ) == _T('e') ) {
buffer.deleteCharAt( buffer.length() - 1 );
}
else if ( buffer.charAt( buffer.length() - 1 ) == _T('s') ) {
buffer.deleteCharAt( buffer.length() - 1 );
}
else if ( buffer.charAt( buffer.length() - 1 ) == _T('n') ) {
buffer.deleteCharAt( buffer.length() - 1 );
}
// "t" occurs only as suffix of verbs.
else if ( buffer.charAt( buffer.length() - 1 ) == _T('t') ) {
buffer.deleteCharAt( buffer.length() - 1 );
}
else {
doMore = false;
}
}
}
void GermanStemmer::optimize(StringBuffer& buffer) {
// Additional step for female plurals of professions and inhabitants.
if ( buffer.length() > 5 && buffer.substringEquals( buffer.length() - 5, buffer.length(), _T("erin*"), 5 ) ) {
buffer.deleteCharAt( buffer.length() -1 );
strip( buffer );
}
// Additional step for irregular plural nouns like "Matrizen -> Matrix".
if ( buffer.charAt( buffer.length() - 1 ) == ( _T('z') ) ) {
buffer.setCharAt( buffer.length() - 1, _T('x') );
}
}
public static void DFS(String digits, List<String> result, StringBuffer s, int start,
HashMap<Integer, String> map) {
if (start == digits.length())
result.add(s.toString());
else {
String tmp = map.get(digits.charAt(start) - '0');
for (int i = 0; i < tmp.length(); i++) {
s.append(tmp.charAt(i));
DFS(digits, result, s, start + 1, map);
s.deleteCharAt(s.length() - 1);
}
}
}
void GermanStemmer::substitute(StringBuffer& buffer) {
substCount = 0;
for ( size_t i = 0; i < buffer.length(); i++ ) {
#ifdef _UCS2
TCHAR c = buffer.charAt(i);
#else
unsigned char c = buffer.charAt(i);
#endif
// Replace the second char of a pair of the equal characters with an asterisk
if ( i > 0 && c == buffer.charAt ( i - 1 ) ) {
buffer.setCharAt( i, _T('*') );
}
// Substitute Umlauts.
else if ( c == 0xe4 ) {
buffer.setCharAt( i, _T('a') );
}
else if ( c == 0xf6 ) {
buffer.setCharAt( i, _T('o') );
}
else if ( c == 0xfc ) {
buffer.setCharAt( i, _T('u') );
}
// Fix bug so that 'ß' at the end of a word is replaced.
else if ( c == 0xdf ) {
buffer.setCharAt( i, _T('s') );
buffer.insert( i + 1, _T('s') );
substCount++;
}
// Take care that at least one character is left left side from the current one
if ( i < buffer.length() - 1 ) {
// Masking several common character combinations with an token
if ( ( i < buffer.length() - 2 ) && c == _T('s') &&
buffer.charAt( i + 1 ) == _T('c') && buffer.charAt( i + 2 ) == _T('h') )
{
buffer.setCharAt( i, _T('$') );
buffer.deleteChars( i + 1, i + 3 );
substCount =+ 2;
}
else if ( c == _T('c') && buffer.charAt( i + 1 ) == _T('h') ) {
buffer.setCharAt( i, 0xa7 ); // section sign in UTF-16
buffer.deleteCharAt( i + 1 );
substCount++;
}
else if ( c == _T('e') && buffer.charAt( i + 1 ) == _T('i') ) {
buffer.setCharAt( i, _T('%') );
buffer.deleteCharAt( i + 1 );
substCount++;
}
else if ( c == _T('i') && buffer.charAt( i + 1 ) == _T('e') ) {
buffer.setCharAt( i, _T('&') );
buffer.deleteCharAt( i + 1 );
substCount++;
}
else if ( c == _T('i') && buffer.charAt( i + 1 ) == _T('g') ) {
buffer.setCharAt( i, _T('#') );
buffer.deleteCharAt( i + 1 );
substCount++;
}
else if ( c == _T('s') && buffer.charAt( i + 1 ) == _T('t') ) {
buffer.setCharAt( i, _T('!') );
buffer.deleteCharAt( i + 1 );
substCount++;
}
}
}
}
void GermanStemmer::substitute(StringBuffer& buffer) {
substCount = 0;
for ( size_t c = 0; c < buffer.length(); c++ ) {
// Replace the second char of a pair of the equal characters with an asterisk
if ( c > 0 && buffer.charAt( c ) == buffer.charAt ( c - 1 ) ) {
buffer.setCharAt( c, _T('*') );
}
// Substitute Umlauts.
else if ( buffer.charAt( c ) == _T('ä') ) {
buffer.setCharAt( c, _T('a') );
}
else if ( buffer.charAt( c ) == _T('ö') ) {
buffer.setCharAt( c, _T('o') );
}
else if ( buffer.charAt( c ) == _T('ü') ) {
buffer.setCharAt( c, _T('u') );
}
// Fix bug so that 'ß' at the end of a word is replaced.
else if ( buffer.charAt( c ) == _T('ß') ) {
buffer.setCharAt( c, _T('s') );
buffer.insert( c + 1, _T('s') );
substCount++;
}
// Take care that at least one character is left left side from the current one
if ( c < buffer.length() - 1 ) {
// Masking several common character combinations with an token
if ( ( c < buffer.length() - 2 ) && buffer.charAt( c ) == _T('s') &&
buffer.charAt( c + 1 ) == _T('c') && buffer.charAt( c + 2 ) == _T('h') )
{
buffer.setCharAt( c, _T('$') );
buffer.deleteChars( c + 1, c + 3 );
substCount =+ 2;
}
else if ( buffer.charAt( c ) == _T('c') && buffer.charAt( c + 1 ) == _T('h') ) {
buffer.setCharAt( c, _T('§') );
buffer.deleteCharAt( c + 1 );
substCount++;
}
else if ( buffer.charAt( c ) == _T('e') && buffer.charAt( c + 1 ) == _T('i') ) {
buffer.setCharAt( c, _T('%') );
buffer.deleteCharAt( c + 1 );
substCount++;
}
else if ( buffer.charAt( c ) == _T('i') && buffer.charAt( c + 1 ) == _T('e') ) {
buffer.setCharAt( c, _T('&') );
buffer.deleteCharAt( c + 1 );
substCount++;
}
else if ( buffer.charAt( c ) == _T('i') && buffer.charAt( c + 1 ) == _T('g') ) {
buffer.setCharAt( c, _T('#') );
buffer.deleteCharAt( c + 1 );
substCount++;
}
else if ( buffer.charAt( c ) == _T('s') && buffer.charAt( c + 1 ) == _T('t') ) {
buffer.setCharAt( c, _T('!') );
buffer.deleteCharAt( c + 1 );
substCount++;
}
}
}
}