Retranslate the complete English edition from Simplified Chinese (#2010)

* Retranslate the complete English edition from Simplified Chinese

* Polish three English explanations after reader-focused review

en/codes/java/utils/ListNode.java

@@ -15,7 +15,7 @@ public class ListNode {
         val = x;
     }
 
-    /* Deserialize a list into a linked list */
+    /* Deserialize an array into a linked list */
     public static ListNode arrToLinkedList(int[] arr) {
         ListNode dum = new ListNode(0);
         ListNode head = dum;

en/codes/java/utils/PrintUtil.java

@@ -19,7 +19,7 @@ class Trunk {
 };
 
 public class PrintUtil {
-    /* Print matrix (Array) */
+    /* Print a matrix (array) */
     public static <T> void printMatrix(T[][] matrix) {
         System.out.println("[");
         for (T[] row : matrix) {
@@ -28,7 +28,7 @@ public class PrintUtil {
         System.out.println("]");
     }
 
-    /* Print matrix (List) */
+    /* Print a matrix (list) */
     public static <T> void printMatrix(List<List<T>> matrix) {
         System.out.println("[");
         for (List<T> row : matrix) {
@@ -37,7 +37,7 @@ public class PrintUtil {
         System.out.println("]");
     }
 
-    /* Print linked list */
+    /* Print a linked list */
     public static void printLinkedList(ListNode head) {
         List<String> list = new ArrayList<>();
         while (head != null) {
@@ -47,13 +47,13 @@ public class PrintUtil {
         System.out.println(String.join(" -> ", list));
     }
 
-    /* Print binary tree */
+    /* Print a binary tree */
     public static void printTree(TreeNode root) {
         printTree(root, null, false);
     }
 
     /**
-     * 打印二叉树
+     * Print a binary tree
      * This tree printer is borrowed from TECHIE DELIGHT
      * https://www.techiedelight.com/c-program-print-binary-tree/
      */
@@ -97,19 +97,19 @@ public class PrintUtil {
         System.out.print(p.str);
     }
 
-    /* Print hash table */
+    /* Print the hash table */
     public static <K, V> void printHashMap(Map<K, V> map) {
         for (Map.Entry<K, V> kv : map.entrySet()) {
             System.out.println(kv.getKey() + " -> " + kv.getValue());
         }
     }
 
-    /* Print heap (priority queue) */
+    /* Print a heap (priority queue) */
     public static void printHeap(Queue<Integer> queue) {
         List<Integer> list = new ArrayList<>(queue);
-        System.out.print("Heap array representation:");
+        System.out.print("Array representation of the heap:");
         System.out.println(list);
-        System.out.println("Heap tree representation:");
+        System.out.println("Tree representation of the heap:");
         TreeNode root = TreeNode.listToTree(list);
         printTree(root);
     }

en/codes/java/utils/TreeNode.java

@@ -12,19 +12,19 @@ import java.util.*;
 public class TreeNode {
     public int val; // Node value
     public int height; // Node height
-    public TreeNode left; // Reference to left child node
-    public TreeNode right; // Reference to right child node
+    public TreeNode left; // Reference to the left child
+    public TreeNode right; // Reference to the right child
 
     /* Constructor */
     public TreeNode(int x) {
         val = x;
     }
 
-    // For the serialization encoding rules, please refer to:
-    // https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
-    // Array representation of binary tree:
+    // For the serialization rules, see:
+    // https://www.hello-algo.com/en/chapter_tree/array_representation_of_tree/
+    // Array representation of the binary tree:
     // [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
-    // Linked list representation of binary tree:
+    // Linked representation of the binary tree:
     //             /——— 15
     //         /——— 7
     //     /——— 3

en/codes/java/utils/Vertex.java

@@ -16,7 +16,7 @@ public class Vertex {
         this.val = val;
     }
 
-    /* Input value list vals, return vertex list vets */
+    /* Given the array of values vals, return the array of vertices vets */
     public static Vertex[] valsToVets(int[] vals) {
         Vertex[] vets = new Vertex[vals.length];
         for (int i = 0; i < vals.length; i++) {
@@ -25,7 +25,7 @@ public class Vertex {
         return vets;
     }
 
-    /* Input vertex list vets, return value list vals */
+    /* Given the list of vertices vets, return the list of values vals */
     public static List<Integer> vetsToVals(List<Vertex> vets) {
         List<Integer> vals = new ArrayList<>();
         for (Vertex vet : vets) {