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/chapter_graph/graph_dfs.cs

@@ -8,7 +8,7 @@ namespace hello_algo.chapter_graph;
 
 public class graph_dfs {
     /* 深度优先遍历 DFS 辅助函数 */
-    public void dfs(GraphAdjList graph, HashSet<Vertex> visited, List<Vertex> res, Vertex vet) {
+    public void Dfs(GraphAdjList graph, HashSet<Vertex> visited, List<Vertex> res, Vertex vet) {
         res.Add(vet);     // 记录访问顶点
         visited.Add(vet); // 标记该顶点已被访问
         // 遍历该顶点的所有邻接顶点
@@ -17,18 +17,18 @@ public class graph_dfs {
                 continue; // 跳过已被访问过的顶点                             
             }
             // 递归访问邻接顶点
-            dfs(graph, visited, res, adjVet);
+            Dfs(graph, visited, res, adjVet);
         }
     }
 
     /* 深度优先遍历 DFS */
     // 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
-    public List<Vertex> graphDFS(GraphAdjList graph, Vertex startVet) {
+    public List<Vertex> GraphDFS(GraphAdjList graph, Vertex startVet) {
         // 顶点遍历序列
-        List<Vertex> res = new List<Vertex>();
+        List<Vertex> res = new();
         // 哈希表，用于记录已被访问过的顶点
-        HashSet<Vertex> visited = new HashSet<Vertex>();
-        dfs(graph, visited, res, startVet);
+        HashSet<Vertex> visited = new();
+        Dfs(graph, visited, res, startVet);
         return res;
     }
 
@@ -42,12 +42,12 @@ public class graph_dfs {
             new Vertex[2] { v[2], v[5] }, new Vertex[2] { v[4], v[5] }, new Vertex[2] { v[5], v[6] },
         };
 
-        GraphAdjList graph = new GraphAdjList(edges);
+        GraphAdjList graph = new(edges);
         Console.WriteLine("\n初始化后，图为");
-        graph.print();
+        graph.Print();
 
         /* 深度优先遍历 DFS */
-        List<Vertex> res = graphDFS(graph, v[0]);
+        List<Vertex> res = GraphDFS(graph, v[0]);
         Console.WriteLine("\n深度优先遍历（DFS）顶点序列为");
         Console.WriteLine(string.Join(" ", Vertex.VetsToVals(res)));
     }