根据读入代码 bool LoadData(ALDirNetwork<char, int>& graph) { ifstream file(

以下是使用C++编写的不使用STL库的带权无向图类的示例代码：

#include <iostream>
#include <fstream>
class ALDirNetwork {
private:
    struct Node {
        char vertex;
        int weight;
        Node* next;
        
        Node(char v, int w) : vertex(v), weight(w), next(nullptr) {}
    };
    struct Vertex {
        char label;
        int weight;
        Node* head;
        Vertex(char l, int w) : label(l), weight(w), head(nullptr) {}
    };
    Vertex* vertices;  // 存储顶点数组
    int numVertices;   // 顶点数量
public:
    ALDirNetwork() : vertices(nullptr), numVertices(0) {}
    ~ALDirNetwork() {
        if (vertices != nullptr) {
            for (int i = 0; i < numVertices; ++i) {
                Node* current = vertices[i].head;
                while (current != nullptr) {
                    Node* temp = current->next;
                    delete current;
                    current = temp;
                }
            }
            delete[] vertices;
        }
    }
    void InsertVex(char v, int w) {
        if (FindVertexIndex(v) == -1) {  // 确保顶点不存在时才插入
            Vertex* newVertices = new Vertex[numVertices + 1];
            for (int i = 0; i < numVertices; ++i)
                newVertices[i] = vertices[i];
            newVertices[numVertices] = { v, w, nullptr };
            ++numVertices;
            delete[] vertices;
            vertices = newVertices;
        }
    }
    void InsertArc(char v1, char v2, int w) {
        int index1 = FindVertexIndex(v1);
        int index2 = FindVertexIndex(v2);
        if (index1 != -1 && index2 != -1) {  // 确保顶点存在才插入边
            Node* newNode = new Node(v2, w);
            newNode->next = vertices[index1].head;
            vertices[index1].head = newNode;
            newNode = new Node(v1, w);
            newNode->next = vertices[index2].head;
            vertices[index2].head = newNode;
        }
    }
    bool LoadData(const char* filename) {
        std::ifstream file(filename);
        if (!file.is_open()) {
            return false;
        }
        int Vexnum, Arcnum;
        file >> Vexnum >> Arcnum; //读入顶点数，弧数目；
        for (int i = 0; i < Vexnum; ++i) {
            char ch;
            int w;
            file >> ch >> w;
            InsertVex(ch, w);      //插入顶点
        }
        for (int i = 0; i < Arcnum; ++i) {
            char v1, v2;
            int w;
            file >> v1 >> v2 >> w;
            InsertArc(v1, v2, w);
        }
		file.close();
        
		return true;
    }
private:
    int FindVertexIndex(char label) const {
        for (int i = 0; i < numVertices; ++i)
            if (vertices[i].label == label)
                return i;
        return -1;  // 找不到返回-1
    }
};
int main() {
   ALDirNetwork graph;
   if (graph.LoadData("map.txt")) {
       // 数据加载成功，可以进行后续操作
   } else {
       // 数据加载失败，处理错误情况
   }
   return 0;
}