Program: 40118
Project: 40118
Buggy source:
private boolean dfsKill(GameMap gameMap,Color color,Color targetColor,int level,Score score,ComboTye comboTye,Set<Point> nextRange,Set<Point> oldRange,Point lastPoint){
  if (System.currentTimeMillis() - startTime > limitTime) {
    result.timeOut=true;
    return false;
  }
  Boolean cacheResult=cache.getComboResult();
  if (cacheResult != null) {
    return cacheResult;
  }
  if (level == 0) {
    return returnValue(false);
  }
  List<Point> rangePoints;
  Set<Point> rangeSet=new HashSet<>();
  if (nextRange != null)   rangeSet.addAll(nextRange);
  if (oldRange != null)   rangeSet.addAll(oldRange);
  if (rangeSet.isEmpty()) {
    rangePoints=gameMap.getNeighbor();
  }
 else {
    rangeSet.remove(lastPoint);
    rangePoints=new ArrayList<>(rangeSet);
  }
  Analyzer data=new Analyzer(gameMap,color,rangePoints,score,false);
  if (comboTye == ComboTye.THREE) {
    if (color == targetColor && !data.getThreeDefence().isEmpty()) {
      comboTye=ComboTye.FOUR;
    }
  }
  if (color == targetColor) {
    if (data.getFiveAttack().size() > 0) {
      return returnValue(true);
    }
    List<Point> points=getComboAttackPoints(data,comboTye);
    for (    Point point : points) {
      setColor(point,color,Color.NULL,targetColor,score,gameMap);
      Set<Point> newNextRange=gameMap.getPointLinesNeighbor(point);
      boolean value=dfsKill(gameMap,color.getOtherColor(),targetColor,level - 1,score,comboTye,newNextRange,nextRange,point);
      if (level == currentLevel && value) {
        result.point=point;
      }
      if (value) {
        setColor(point,Color.NULL,color,targetColor,score,gameMap);
        return returnValue(true);
      }
      setColor(point,Color.NULL,color,targetColor,score,gameMap);
    }
    return returnValue(false);
  }
 else {
    if (data.getFiveAttack().size() > 0) {
      return returnValue(false);
    }
    List<Point> points=getComboDefencePoints(data,comboTye);
    if (points.size() == 0) {
      return returnValue(false);
    }
    for (    Point point : points) {
      setColor(point,color,Color.NULL,targetColor,score,gameMap);
      Set<Point> newNextRange=gameMap.getPointLinesNeighbor(point);
      boolean value=dfsKill(gameMap,color.getOtherColor(),targetColor,level - 1,score,comboTye,newNextRange,nextRange,point);
      if (!value) {
        setColor(point,Color.NULL,color,targetColor,score,gameMap);
        return returnValue(false);
      }
      setColor(point,Color.NULL,color,targetColor,score,gameMap);
    }
    return returnValue(true);
  }
}

Fixed version (ground truth):
private boolean dfsKill(GameMap gameMap,Color color,Color targetColor,int level,Score score,ComboTye comboTye,Set<Point> nextRange,Set<Point> oldRange,Point lastPoint){
  if (System.currentTimeMillis() - startTime > limitTime) {
    result.timeOut=true;
    return false;
  }
  Boolean cacheResult=cache.getComboResult();
  if (cacheResult != null) {
    return cacheResult;
  }
  if (level == 0) {
    return returnValue(false);
  }
  List<Point> rangePoints;
  Set<Point> rangeSet=new HashSet<>();
  if (nextRange != null)   rangeSet.addAll(nextRange);
  if (oldRange != null)   rangeSet.addAll(oldRange);
  if (rangeSet.isEmpty()) {
    rangePoints=gameMap.getNeighbor();
  }
 else {
    rangeSet.remove(lastPoint);
    rangePoints=new ArrayList<>(rangeSet);
  }
  Analyzer data=new Analyzer(gameMap,color,rangePoints,score,true);
  if (comboTye == ComboTye.THREE) {
    if (color == targetColor && !data.getThreeDefence().isEmpty()) {
      comboTye=ComboTye.FOUR;
    }
  }
  if (color == targetColor) {
    if (data.getFiveAttack().size() > 0) {
      if (level == currentLevel) {
        result.point=data.getFiveAttack().iterator().next();
      }
      return returnValue(true);
    }
    List<Point> points=getComboAttackPoints(data,comboTye);
    for (    Point point : points) {
      setColor(point,color,Color.NULL,targetColor,score,gameMap);
      Set<Point> newNextRange=gameMap.getPointLinesNeighbor(point);
      boolean value=dfsKill(gameMap,color.getOtherColor(),targetColor,level - 1,score,comboTye,newNextRange,nextRange,point);
      if (level == currentLevel && value) {
        result.point=point;
      }
      if (value) {
        setColor(point,Color.NULL,color,targetColor,score,gameMap);
        return returnValue(true);
      }
      setColor(point,Color.NULL,color,targetColor,score,gameMap);
    }
    return returnValue(false);
  }
 else {
    if (data.getFiveAttack().size() > 0) {
      return returnValue(false);
    }
    List<Point> points=getComboDefencePoints(data,comboTye);
    if (points.size() == 0) {
      return returnValue(false);
    }
    for (    Point point : points) {
      setColor(point,color,Color.NULL,targetColor,score,gameMap);
      Set<Point> newNextRange=gameMap.getPointLinesNeighbor(point);
      boolean value=dfsKill(gameMap,color.getOtherColor(),targetColor,level - 1,score,comboTye,newNextRange,nextRange,point);
      if (!value) {
        setColor(point,Color.NULL,color,targetColor,score,gameMap);
        return returnValue(false);
      }
      setColor(point,Color.NULL,color,targetColor,score,gameMap);
    }
    return returnValue(true);
  }
}