RosettaCodeData/Task/Amb/Java/amb.java

53 lines
1.5 KiB
Java

import java.util.ArrayList;
import java.util.List;
import java.util.function.BiFunction;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public final class AmbTask {
public static void main(String[] aArgs) {
List<List<String>> words = List.of(
List.of( "the", "that", "a" ),
List.of( "frog", "elephant", "thing" ),
List.of( "walked", "treaded", "grows" ),
List.of( "slowly", "quickly" ) );
System.out.println(Amb(words));
}
private static String Amb(List<List<String>> aOptions) {
BiFunction<String, String, Boolean> continues = (before, after) -> before.endsWith(after.substring(0, 1));
List<String> ambResult = amb(continues, aOptions, "");
return ( ambResult.isEmpty() ) ? "No match found" : String.join(" ", ambResult);
}
private static List<String> amb(
BiFunction<String, String, Boolean> aBiFunction, List<List<String>> aOptions, String aPrevious) {
if ( aOptions.isEmpty() ) {
return new ArrayList<String>();
}
for ( String option : aOptions.get(0) ) {
if ( ! aPrevious.isEmpty() && ! aBiFunction.apply(aPrevious, option) ) {
continue;
}
if ( aOptions.size() == 1 ) {
return Stream.of(option).collect(Collectors.toList());
}
List<String> result = (ArrayList<String>) amb(aBiFunction, aOptions.subList(1, aOptions.size()), option);
if ( ! result.isEmpty() ) {
result.add(0, option);
return result;
}
}
return new ArrayList<String>();
}
}