Sorting a string LinkedList in Java is easy. You can sort the string LinkedList in ascending alphabetical order by using sort(List<T> list) . You can also sort the string LinkedList in descending alphabetical order by using sort(List<T> list, Comparator<? super T> c) . Here is the code: public static void main(String[] args) { LinkedList<String> stringList … Read more
This code is for showing how to sort a Double LinkedList in Java. You can use sort(List<T> list) method. It will sort the double list in ascending order. If you want to sort it in descending order, you can use sort(List<T> list, Comparator<? super T> c) . public static void main(String[] args) { LinkedList<Double> doubleList … Read more
To keep the unique value of a large data set, Set would be a good option. Every element in a set is unique, when a duplicate element is added, it is ignored. Here is a sample code from oracle. public class FindDups2 { public static void main(String[] args) { Set<String> uniques = new HashSet<String>(); Set<String> … Read more
Implement Comparable for a TreeSet
In Java, the PriorityQueue class is implemented as a priority heap. Heap is an important data structure in computer science. For a quick overview of heap, here is a very good tutorial. 1. Simple Example The following examples shows the basic operations of PriorityQueue such as offer(), peek(), poll(), and size(). import java.util.Comparator; import java.util.PriorityQueue; … Read more
1. Collection vs Collections First of all, “Collection” and “Collections” are two different concepts. As you will see from the hierarchy diagram below, “Collection” is a root interface in the Collection hierarchy but “Collections” is a class which provide static methods to manipulate on some Collection types. 2. Class hierarchy of Collection The following diagram … Read more
What is the result of the following program? import java.util.Scanner; public class Looking { public static void main(String[] args){ String input = "1 2 a 3 45 6"; Scanner sc = new Scanner(input); int x = 0; do{ x = sc.nextInt(); System.out.print(x + " "); }while(x != 0); } }import java.util.Scanner; public class Looking { … Read more