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Articles by karthikeya Boyini
Page 65 of 143
Remove all elements from Java LinkedHashSet
To remove all the elements from LinkedHashSet in Java, use the clear() method.The following is an example to declare LinkedHashSet and add elements to it −LinkedHashSet hashSet = new LinkedHashSet(); hashSet.add(10); hashSet.add(20); hashSet.add(30); hashSet.add(40); hashSet.add(50); hashSet.add(60);Use the clear() method to remove all elements −hashSet.clear();The following is an example −Exampleimport java.util.LinkedHashSet; public class Demo { public static void main(String[] args) { LinkedHashSet hashSet = new LinkedHashSet(); hashSet.add(10); hashSet.add(20); hashSet.add(30); ...
Read MoreGet last entry from NavigableMap in Java
To display the last entry from NavigableMap in Java, use the lastEntry() method.Let us first create NavigableMap.NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); n.put("C", 868); n.put("D", 988); n.put("E", 686); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);Get the last entry now.n.lastEntry()The following is an example to get the last entry from NavigableMap.Exampleimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); ...
Read MoreJava Program to generate custom random number -1 or 1
To generate custom random number 1 or -1, you need to use nextBoolean(). At first take a loop and create a Random object on each iteration −for (int i = 0; i < 5; i++) { Random rand = new Random(); }Now, use nextBoolean() to generate 1 on TRUE condition, ekse -1 −for (int i = 0; i < 5; i++) { Random rand = new Random(); if (rand.nextBoolean()) System.out.println(1); else System.out.println(-1); }Exampleimport java.util.Random; public class Demo { public static void main(String[] args) { for (int ...
Read MoreC++ Program to Construct an Expression Tree for a Postfix Expression
An expression tree is basically a binary tree which is used to represent expressions. In expression tree, nodes correspond to the operator and each leaf node corresponds to the operand. This is a C++ program to construct an expression tree for a postfix Expression in inorder, preorder and postorder traversals.AlgorithmBegin Function r() has a character variable as parameter. If the characters are + or - or * or / then Return will be -1 If the characters are from A to Z then Return will ...
Read MoreHow to use headSet() method of Java NavigableSet Class
The headset() method returns elements up to a limit defined as a parameter.First, create a NavigableSet and add elements −NavigableSet set = new TreeSet(); set.add(10); set.add(25); set.add(40); set.add(55); set.add(70); set.add(85); set.add(100);Now, use the headset() method −set.headSet(55));The following is an example −Exampleimport java.util.NavigableSet; import java.util.TreeSet; public class Demo { public static void main(String[] args) { NavigableSet set = new TreeSet(); set.add(10); set.add(25); set.add(40); set.add(55); set.add(70); set.add(85); set.add(100); System.out.println("Returned Value = " + set.headSet(55)); ...
Read MoreCopy all elements of Java LinkedHashSet to an Object Array
First, create a LinkedHashSet and add elements −LinkedHashSet l = new LinkedHashSet(); l.add(new String("1")); l.add(new String("2")); l.add(new String("3")); l.add(new String("4")); l.add(new String("5")); l.add(new String("6")); l.add(new String("7"));Now, copy it to an object array like this −// copying Object[] arr = l.toArray();The following is an example to copy all elements of a LinkedHashSet to an object array −Exampleimport java.util.*; public class Demo { public static void main(String[] args) { LinkedHashSet l = new LinkedHashSet(); l.add(new String("1")); l.add(new String("2")); ...
Read MoreC++ Program to Find Lowest Common Ancestor in a Binary Search Tree
A binary tree which has at most two children, specified as left child and right child. This is a C++ Program to find the lowest common ancestor in a Binary Tree.AlgorithmBegin Create a structure n to declare data d, a left child pointer l and a right child pointer r. Create a function to create newnode. Call a function LCA() to Find lowest common ancestor in a binary tree: Assume node n1 and n2 present in the tree. If root is null, then return. If root is not null there are two cases. ...
Read MoreCreate a new ArrayList from another collection in Java
An ArrayList can be created from another collection using the java.util.Arrays.asList() method. A program that demonstrates this is given as follows −Exampleimport java.util.ArrayList; import java.util.Arrays; import java.util.List; public class Demo { public static void main(String args[]) throws Exception { String str[] = { "John", "Macy", "Peter", "Susan", "Lucy" }; List aList = new ArrayList(Arrays.asList(str)); System.out.println("The ArrayList elements are: " + aList); } }OutputThe ArrayList elements are: [John, Macy, Peter, Susan, Lucy]Now let us understand the above program.The string array str[] is defined. Then an ArrayList is created using the ...
Read MoreHow to populate a 2d array with random alphabetic values from a range in Java?
To populate a 2d array with random alphabets, use the Random class. Let us first declare a 2d array −char arr[][] = new char[3][3];Now, in a nested for loop, use the Random class object to get random values on the basis of switch case. Here, our range is 3 i.e. set of 3 alphabets at once −Random randNum = new Random(); for (int i = 0; i < 3; i++) { for (int j = 0; j < 3; j++) { int x = randNum.nextInt(3); switch (x) { case ...
Read MoreJava Program to sort a subset of array elements
Let us first create a string array −String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" };Now, use Arrays.sort() to get the subset. Use the following to sort only from the index range 2 to 6.Arrays.sort(strArr, 2, 6);Exampleimport java.util.Arrays; public class Demo { public static void main(String[] args) { String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" }; Arrays.sort(strArr, 2, 6); System.out.println("Sorted subset of array elements from index 2 to 6..."); for (int a = 0; a < strArr.length; a++) ...
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