Sorting points(in 2d,3d and so on) in java

Question

What is the best way to sort the points(first based on x co-ordinate and if x is same then on y co-ordinate and if y is same then based on z co-ordinate and so on.) in java without implementing sorting algorithm?

In c++ it can be done very easily(as follows) with the help of pairs.

For 2D:

Vector < pair < int,int > > plane;
sort(plane.begin(),plane.end())

For 3D:

Vector < pair < int,pair < int,int > > > space;
sort(space.begin(),space.end());

Thanks in Advance. Shantanu

Answer 1

You don't need to implement a sorting algorithm. You just need to implement a comparator, which can then be used with Collections.sort() .

See Object Ordering from the Java Tutorial for more information.

Answer 2

There are few options in Java.

1. Collections.sort(List l)

   Use java.lang.Comparable // For sorting only on the basis of one property

2. Collections.sort(List l, Comparator c)

   Use java.util.Comparator // For sorting in more than one way

3. If Uniqueness is needed, along with Sorting use TreeSet()

    TreeSet() // Sorting in Natural order TreeSet(Comparator c) // Sorting in more than one way.