Java 我试着按字典顺序排列矩形。(x、y、宽度、高度)
如果矩形具有相同的x值,则比较y值,然后检查宽度和高度等Java 我试着按字典顺序排列矩形。(x、y、宽度、高度),java,comparator,lexicographic,Java,Comparator,Lexicographic,如果矩形具有相同的x值,则比较y值,然后检查宽度和高度等 public class RectangleTester { public static void main(String[] args) { ArrayList<Rectangle2D> list = new ArrayList<>(); list.add(new Rectangle2D.Double(100,100,50,50)); list.ad
public class RectangleTester
{
public static void main(String[] args)
{
ArrayList<Rectangle2D> list = new ArrayList<>();
list.add(new Rectangle2D.Double(100,100,50,50));
list.add(new Rectangle2D.Double(120,80,54,75));
list.add(new Rectangle2D.Double(85,95,60,55));
list.add(new Rectangle2D.Double(100,95,55,55));
list.add(new Rectangle2D.Double(100,95,55,52));
System.out.println("\nUnsorted Rectangles:");
for (Rectangle2D temp : list)
System.out.println(temp.toString() + " Y: " + temp.getY());
如您所见,使用x值对矩形进行了正确排序,但当多个矩形具有相同的x值时,排序无法将它们按正确的顺序排列。如果我的if语句有逻辑性,我就需要另一双眼睛 第一个错误,您正在将对象与
=
进行比较<代码>=比较引用,而不是值
第二个错误,你的逻辑是错误的,不必要的复杂。只需按照您描述的方式实现它:如果矩形具有相同的x值,则比较y值:
有了番石榴,就可以很容易地用
return ComparisonChain.start()
.compare(r1X, r2X)
.compare(r1Y, r2Y)
.compare(r1Width, r2Width)
.compare(r1Height, r2Height)
.result();
使用Java 8,它将更加干净:
Comparator<Rectangle> comparator =
Comparator.comparing(Rectangle::getX)
.thenComparing(Rectangle::getY)
.thenComparing(Rectangle::getWidth)
.thenComparing(Rectangle::getHeight)
比较器比较器=
Comparator.comparing(矩形::getX)
.Then比较(矩形::getY)
.Then比较(矩形::getWidth)
.Then比较(矩形::getHeight)
LOL。我真是个比较那样的东西的白痴。难怪我的逻辑都不起作用。上面的代码只是我尝试的最新代码。我的原创很像你的。谢谢你指出我的错误。
int result = r1X.compareTo(r2X);
if (result == 0) {
result = r1Y.compareTo(r2Y);
}
if (result == 0) {
result = r1Width.compareTo(r2Width);
}
if (result == 0) {
result = r1Height.compareTo(r2Height);
}
return result;
return ComparisonChain.start()
.compare(r1X, r2X)
.compare(r1Y, r2Y)
.compare(r1Width, r2Width)
.compare(r1Height, r2Height)
.result();
Comparator<Rectangle> comparator =
Comparator.comparing(Rectangle::getX)
.thenComparing(Rectangle::getY)
.thenComparing(Rectangle::getWidth)
.thenComparing(Rectangle::getHeight)