refactor: use global using to reduce usings in each file (#486)

codes/csharp/GlobalUsing.cs

@@ -0,0 +1,2 @@
+global using NUnit.Framework;
+global using hello_algo.utils;

codes/csharp/chapter_array_and_linkedlist/array.cs

@@ -2,8 +2,6 @@
 // Created Time: 2022-12-14
 // Author: mingXta (1195669834@qq.com)
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_array_and_linkedlist;
 
 public class array {

codes/csharp/chapter_array_and_linkedlist/linked_list.cs

@@ -2,9 +2,6 @@
 // Created Time: 2022-12-16
 // Author: mingXta (1195669834@qq.com)
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_array_and_linkedlist;
 
 public class linked_list {

codes/csharp/chapter_array_and_linkedlist/list.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_array_and_linkedlist;
 
 public class list {

codes/csharp/chapter_array_and_linkedlist/my_list.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_array_and_linkedlist;
 
 /* 列表类简易实现 */

codes/csharp/chapter_backtracking/n_queens.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class n_queens {

codes/csharp/chapter_backtracking/permutations_i.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class permutations_i {

codes/csharp/chapter_backtracking/permutations_ii.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class permutations_ii {

codes/csharp/chapter_backtracking/preorder_traversal_i_compact.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class preorder_traversal_i_compact {

codes/csharp/chapter_backtracking/preorder_traversal_ii_compact.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class preorder_traversal_ii_compact {

codes/csharp/chapter_backtracking/preorder_traversal_iii_compact.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class preorder_traversal_iii_compact {

codes/csharp/chapter_backtracking/preorder_traversal_iii_template.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_backtracking;
 
 public class preorder_traversal_iii_template {

codes/csharp/chapter_binary_search/binary_search.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_binary_search;
 
 public class binary_search {

codes/csharp/chapter_computational_complexity/space_complexity.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_computational_complexity;
 
 public class space_complexity {

codes/csharp/chapter_computational_complexity/time_complexity.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_computational_complexity;
 
 public class time_complexity {

codes/csharp/chapter_computational_complexity/worst_best_time_complexity.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_computational_complexity;
 
 public class worst_best_time_complexity {

codes/csharp/chapter_graph/graph_adjacency_list.cs

@@ -4,9 +4,6 @@
  * Author: zjkung1123 (zjkung1123@gmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_graph;
 
 /* 基于邻接表实现的无向图类 */

codes/csharp/chapter_graph/graph_adjacency_matrix.cs

@@ -4,9 +4,6 @@
  * Author: zjkung1123 (zjkung1123@gmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_graph;
 
 /* 基于邻接矩阵实现的无向图类 */

codes/csharp/chapter_graph/graph_bfs.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_graph;
 
 public class graph_bfs {

codes/csharp/chapter_graph/graph_dfs.cs

@@ -4,9 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_graph;
 
 public class graph_dfs {

codes/csharp/chapter_hashing/array_hash_map.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_hashing;
 
 /* 键值对 int->string */

codes/csharp/chapter_hashing/hash_map.cs

@@ -5,9 +5,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_hashing;
 
 public class hash_map {

codes/csharp/chapter_heap/heap.cs

@@ -4,9 +4,6 @@
  * Author: zjkung1123 (zjkung1123@gmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_heap;
 
 public class heap {

codes/csharp/chapter_heap/my_heap.cs

@@ -4,9 +4,6 @@
  * Author: zjkung1123 (zjkung1123@gmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_heap;
 
 /* 大顶堆 */

codes/csharp/chapter_searching/hashing_search.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_searching;
 
 public class hashing_search {

codes/csharp/chapter_searching/leetcode_two_sum.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_searching;
 
 public class leetcode_two_sum {

codes/csharp/chapter_searching/linear_search.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_searching;
 
 public class linear_search {

codes/csharp/chapter_sorting/bubble_sort.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class bubble_sort {

codes/csharp/chapter_sorting/bucket_sort.cs

@@ -4,8 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class bucket_sort {

codes/csharp/chapter_sorting/counting_sort.cs

@@ -4,8 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class counting_sort {

codes/csharp/chapter_sorting/insertion_sort.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class insertion_sort {

codes/csharp/chapter_sorting/merge_sort.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class merge_sort {

codes/csharp/chapter_sorting/quick_sort.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 class QuickSort {

codes/csharp/chapter_sorting/radix_sort.cs

@@ -4,8 +4,6 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_sorting;
 
 public class radix_sort {

codes/csharp/chapter_stack_and_queue/array_deque.cs

@@ -4,11 +4,10 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using NUnit.Framework;
+namespace hello_algo.chapter_stack_and_queue;
 
-namespace hello_algo.chapter_stack_and_queue {
+/* 基于环形数组实现的双向队列 */
-    /* 基于环形数组实现的双向队列 */
+public class ArrayDeque {
-    public class ArrayDeque {
     private readonly int[] nums;  // 用于存储双向队列元素的数组
     private int front;   // 队首指针，指向队首元素
     private int queSize; // 双向队列长度
@@ -112,9 +111,9 @@ namespace hello_algo.chapter_stack_and_queue {
         }
         return res;
     }
-    }
+}
 
-    public class array_deque {
+public class array_deque {
     [Test]
     public void Test() {
         /* 初始化双向队列 */
@@ -150,5 +149,4 @@ namespace hello_algo.chapter_stack_and_queue {
         bool isEmpty = deque.isEmpty();
         Console.WriteLine("双向队列是否为空 = " + isEmpty);
     }
-    }
 }

codes/csharp/chapter_stack_and_queue/array_queue.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 /* 基于环形数组实现的队列 */

codes/csharp/chapter_stack_and_queue/array_stack.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 /* 基于数组实现的栈 */

codes/csharp/chapter_stack_and_queue/deque.cs

@@ -4,8 +4,6 @@
  * Author: moonache (microin1301@outlook.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 public class deque {

codes/csharp/chapter_stack_and_queue/linkedlist_deque.cs

@@ -4,11 +4,10 @@
  * Author: hpstory (hpstory1024@163.com)
  */
 
-using NUnit.Framework;
+namespace hello_algo.chapter_stack_and_queue;
 
-namespace hello_algo.chapter_stack_and_queue {
+/* 双向链表节点 */
-    /* 双向链表节点 */
+public class ListNode {
-    public class ListNode {
     public int val;       // 节点值
     public ListNode? next; // 后继节点引用（指针）
     public ListNode? prev; // 前驱节点引用（指针）
@@ -18,10 +17,10 @@ namespace hello_algo.chapter_stack_and_queue {
         prev = null;
         next = null;
     }
-    }
+}
 
-    /* 基于双向链表实现的双向队列 */
+/* 基于双向链表实现的双向队列 */
-    public class LinkedListDeque {
+public class LinkedListDeque {
     private ListNode? front, rear; // 头节点 front, 尾节点 rear
     private int queSize = 0;      // 双向队列的长度
 
@@ -144,9 +143,9 @@ namespace hello_algo.chapter_stack_and_queue {
 
         return res;
     }
-    }
+}
 
-    public class linkedlist_deque {
+public class linkedlist_deque {
     [Test]
     public void Test() {
         /* 初始化双向队列 */
@@ -182,5 +181,4 @@ namespace hello_algo.chapter_stack_and_queue {
         bool isEmpty = deque.isEmpty();
         Console.WriteLine("双向队列是否为空 = " + isEmpty);
     }
-    }
 }

codes/csharp/chapter_stack_and_queue/linkedlist_queue.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 /* 基于链表实现的队列 */

codes/csharp/chapter_stack_and_queue/linkedlist_stack.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 /* 基于链表实现的栈 */

codes/csharp/chapter_stack_and_queue/queue.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 public class queue {

codes/csharp/chapter_stack_and_queue/stack.cs

@@ -4,8 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using NUnit.Framework;
-
 namespace hello_algo.chapter_stack_and_queue;
 
 public class stack {

codes/csharp/chapter_tree/avl_tree.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_tree;
 
 /* AVL 树 */

codes/csharp/chapter_tree/binary_search_tree.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_tree;
 
 class BinarySearchTree {

codes/csharp/chapter_tree/binary_tree.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_tree;
 
 public class binary_tree {

codes/csharp/chapter_tree/binary_tree_bfs.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_tree;
 
 public class binary_tree_bfs {

codes/csharp/chapter_tree/binary_tree_dfs.cs

@@ -4,9 +4,6 @@
  * Author: haptear (haptear@hotmail.com)
  */
 
-using hello_algo.utils;
-using NUnit.Framework;
-
 namespace hello_algo.chapter_tree;
 
 public class binary_tree_dfs {