feat: Revised the book (#978)

* Sync recent changes to the revised Word.

* Revised the preface chapter

* Revised the introduction chapter

* Revised the computation complexity chapter

* Revised the chapter data structure

* Revised the chapter array and linked list

* Revised the chapter stack and queue

* Revised the chapter hashing

* Revised the chapter tree

* Revised the chapter heap

* Revised the chapter graph

* Revised the chapter searching

* Reivised the sorting chapter

* Revised the divide and conquer chapter

* Revised the chapter backtacking

* Revised the DP chapter

* Revised the greedy chapter

* Revised the appendix chapter

* Revised the preface chapter doubly

* Revised the figures

codes/swift/chapter_graph/graph_bfs.swift

@@ -23,7 +23,7 @@ func graphBFS(graph: GraphAdjList, startVet: Vertex) -> [Vertex] {
         // 遍历该顶点的所有邻接顶点
         for adjVet in graph.adjList[vet] ?? [] {
             if visited.contains(adjVet) {
-                continue // 跳过已被访问过的顶点
+                continue // 跳过已被访问的顶点
             }
             que.append(adjVet) // 只入队未访问的顶点
             visited.insert(adjVet) // 标记该顶点已被访问