fix(csharp): Modify method name to PascalCase, simplify new expression (#840)

* Modify method name to PascalCase(array and linked list)

* Modify method name to PascalCase(backtracking)

* Modify method name to PascalCase(computational complexity)

* Modify method name to PascalCase(divide and conquer)

* Modify method name to PascalCase(dynamic programming)

* Modify method name to PascalCase(graph)

* Modify method name to PascalCase(greedy)

* Modify method name to PascalCase(hashing)

* Modify method name to PascalCase(heap)

* Modify method name to PascalCase(searching)

* Modify method name to PascalCase(sorting)

* Modify method name to PascalCase(stack and queue)

* Modify method name to PascalCase(tree)

* local check

codes/csharp/utils/ListNode.cs

@@ -15,7 +15,7 @@ public class ListNode {
 
     /* Generate a linked list with an array */
     public static ListNode? ArrToLinkedList(int[] arr) {
-        ListNode dum = new ListNode(0);
+        ListNode dum = new(0);
         ListNode head = dum;
         foreach (int val in arr) {
             head.next = new ListNode(val);

codes/csharp/utils/PrintUtil.cs

@@ -70,7 +70,7 @@ public static class PrintUtil {
         }
 
         string prev_str = "    ";
-        Trunk trunk = new Trunk(prev, prev_str);
+        Trunk trunk = new(prev, prev_str);
 
         PrintTree(root.right, trunk, true);
 
@@ -126,8 +126,8 @@ public static class PrintUtil {
     public static void PrintHeap(PriorityQueue<int, int> queue) {
         var newQueue = new PriorityQueue<int, int>(queue.UnorderedItems, queue.Comparer);
         Console.Write("堆的数组表示：");
-        List<int> list = new List<int>();
-        while (newQueue.TryDequeue(out int element, out int priority)) {
+        List<int> list = new();
+        while (newQueue.TryDequeue(out int element, out _)) {
             list.Add(element);
         }
         Console.WriteLine("堆的树状表示：");

codes/csharp/utils/TreeNode.cs

@@ -39,9 +39,10 @@ public class TreeNode {
         if (i < 0 || i >= arr.Count || !arr[i].HasValue) {
             return null;
         }
-        TreeNode root = new TreeNode(arr[i].Value);
-        root.left = ListToTreeDFS(arr, 2 * i + 1);
-        root.right = ListToTreeDFS(arr, 2 * i + 2);
+        TreeNode root = new(arr[i].Value) {
+            left = ListToTreeDFS(arr, 2 * i + 1),
+            right = ListToTreeDFS(arr, 2 * i + 2)
+        };
         return root;
     }
 
@@ -63,8 +64,8 @@ public class TreeNode {
     }
 
     /* 将二叉树序列化为列表 */
-    public static List<int?> treeToList(TreeNode root) {
-        List<int?> res = new List<int?>();
+    public static List<int?> TreeToList(TreeNode root) {
+        List<int?> res = new();
         TreeToListDFS(root, 0, res);
         return res;
     }

codes/csharp/utils/Vertex.cs

@@ -24,7 +24,7 @@ public class Vertex {
 
     /* 输入顶点列表 vets ，返回值列表 vals */
     public static List<int> VetsToVals(List<Vertex> vets) {
-        List<int> vals = new List<int>();
+        List<int> vals = new();
         foreach (Vertex vet in vets) {
             vals.Add(vet.val);
         }