!747

m {
  static S sentence1 = "Yes is the opposite of no. No is the opposite of yes.";
  static S sentence2 = "Green is the opposite of white.";
  
  !include #1000988 // MultiSet
  
  p {
    L<S> tok1 = parse(sentence1);
    L<S> tok2 = parse(sentence2);
    
    Map<S, MultiSet<S>> map = makeMMapPrefix(tok1, tok2);
    if (map == null)
      print("No match.");
    else
      print(structure(map));
      
    print(complete(sentence1, sentence2));
  }
  
  static L<S> parse(S s) {
    return tokensToLowerCase(javaTok(s));
  }
  
  static S complete(S sentence1, S sentence2) {
    L<S> tok1 = parse(sentence1);
    L<S> tok2 = parse(sentence2);
    Map<S, MultiSet<S>> map = makeMMapPrefix(tok1, tok2);
    if (map == null) return null;
    new L<S> tok;
    tok.addAll(tok2.subList(0, tok2.size()-1));
    for (int i = tok2.size()-1; i < tok1.size(); i++) {
      S t = tok1.get(i);
      MultiSet<S> set = map.get(t);
      tok.add(set == null ? t : set.getMostPopularEntry());
    }
    return join(tok);
  }
  
  static Map<S, MultiSet<S>> makeMMapPrefix(L<S> tok1, L<S> tok2) {
    if (tok1.size() < tok2.size()) return null;
    
    Map<S, MultiSet<S>> map = new TreeMap<S, MultiSet<S>>();
    for (int i = 1; i < tok2.size(); i += 2) {
      S t1 = tok1.get(i), t2 = tok2.get(i);
      MultiSet<S> set = map.get(t1);
      if (set == null)
        map.put(t1, new MultiSet<S>(t2));
      else
        set.add(t2);
    }
    
    // match succeeds
    return map;
  }
}

Began life as a copy of #1000986