Tree Transvering

Description

https://www.youtube.com/watch?v=-SF2e7cDev0&feature=youtu.be   Please look this video and start the work. Please do not modify the TreeNode.Java file and also please do not create any other java file. Just use the TreeNode and Autocomplete.java to complete question 1 2 3. but please look the video first. Fill it your code where it says “fill it here”   Here is the TreeNode.java file // DO NOT MODIFY THIS FILE // DO NOT MODIFY THIS FILE // DO NOT MODIFY THIS FILE // DO NOT MODIFY THIS FILE import java.util.*;   public class TreeNode<T> { private T value; private List<TreeNode<T>> children;   public TreeNode(T value) { this.value = value; this.children = new ArrayList<>(); }   public TreeNode(T value, List<TreeNode<T>> children) { assert children != null : “children cannot be null”; this.value = value; this.children = children; }   public T getValue() { return value; }   public List<TreeNode<T>> getChildren() { return children; }   public boolean isLeaf() { return children == null || children.size() == 0; } }   And here is the AutoComplete.Java file below    import java.util.*;   public class Autocomplete {     public static void main(String[] args) { TreeNode<Character> example = makeExample();   // Q1 Examples //TreeNode<Character> endNode = findNode(example, “acn”, 0); //System.out.println(endNode.getValue()); // should output ‘n’ //System.out.println(endNode.getChildren().get(0).getValue()); // should output ‘e’   //endNode = findNode(example, “notInTree”, 0); //System.out.println(endNode); // should output null   // Q2 Examples //List<String> exampleList = new ArrayList<>(); //collectWords(example.getChildren().get(1), “”, exampleList); //System.out.println(exampleList); // should output [“eam”, “eef”, “ees”]   // exampleList.clear(); //collectWords(example.getChildren().get(1), “b”, exampleList); //System.out.println(exampleList); // should output [“beam”, “beef”, “bees”]   // exampleList.clear(); //collectWords(example.getChildren().get(1), “mm”, exampleList); //System.out.println(exampleList); // should output [“mmeam”, “mmeef”, “mmees”]   // Q3 Examples //System.out.println(candidates(example, “c”)); // Outputs [“cat”, “cow”, “cut”] //System.out.println(candidates(example, “ca”)); // Outputs [“cat”] //System.out.println(candidates(example, “an”)); // Outputs [“and”, “andrew”]   //// Outputs [“ace”, “acne”, “and”, “andrew”, “beam”, “beef”, “bees”, “cat”, “cow”, “cut”] //System.out.println(candidates(example, “”)); //System.out.println(candidates(example, “deer”)); // Outputs [] //System.out.println(candidates(example, “bean”)); // Outputs [] }     /* * Q1. findNode * Add your key ideas to this comment. * How did you approach the problem? * Why does your code work? */ public static TreeNode<Character> findNode(TreeNode<Character> node, String prefix, int index) {  //fill it here your code   throw new UnsupportedOperationException(“findNode not yet written”);  //fill it here your code }   /* * Q2. collectWords * Add your key ideas to this comment. * How did you approach the problem? * Why does your code work? */ public static void collectWords(TreeNode<Character> node, String prefix, List<String> results) { // fill it here your code throw new UnsupportedOperationException(“collectWords not yet written”); //fill it here your code   }   /* * Q3. candidates * Add your key ideas to this comment. * How did you approach the problem? * Why does your code work? */ public static List<String> candidates(TreeNode<Character> root, String prefix) { //fill it here your code throw new UnsupportedOperationException(“candidates not yet written”); //fill it here your code }   private static TreeNode<Character> makeExample() { return new TreeNode(‘*’, Arrays.asList( new TreeNode(‘a’, Arrays.asList( new TreeNode(‘c’, Arrays.asList( new TreeNode(‘e’, Arrays.asList( new TreeNode(‘$’) )), new TreeNode(‘n’, Arrays.asList( new TreeNode(‘e’, Arrays.asList( new TreeNode(‘$’) )) )) )), new TreeNode(‘n’, Arrays.asList( new TreeNode(‘d’, Arrays.asList( new TreeNode(‘$’), new TreeNode(‘r’, Arrays.asList( new TreeNode(‘e’, Arrays.asList( new TreeNode(‘w’, Arrays.asList( new TreeNode(‘$’) )) )) )) )) )) )), new TreeNode(‘b’, Arrays.asList( new TreeNode(‘e’, Arrays.asList( new TreeNode(‘a’, Arrays.asList( new TreeNode(‘m’, Arrays.asList( new TreeNode(‘$’) )) )), new TreeNode(‘e’, Arrays.asList( new TreeNode(‘f’, Arrays.asList( new TreeNode(‘$’) )), new TreeNode(‘s’, Arrays.asList( new TreeNode(‘$’) )) )) )) )), new TreeNode(‘c’, Arrays.asList( new TreeNode(‘a’, Arrays.asList( new TreeNode(‘t’, Arrays.asList( new TreeNode(‘$’) )) )), new TreeNode(‘o’, Arrays.asList( new TreeNode(‘w’, Arrays.asList( new TreeNode(‘$’) )) )), new TreeNode(‘u’, Arrays.asList( new TreeNode(‘t’, Arrays.asList( new TreeNode(‘$’) )) )) )) )); }   }