如何在c++中增加邻接表的最大长度？

struct Node {
    int vertex;
    Node* next;
};

struct Graph {
    int numVertices;
    Node** adjLists;
};

Graph* createGraph(int numVertices) {
    Graph* graph = new Graph;
    graph->numVertices = numVertices;

    graph->adjLists = new Node*[numVertices];
    for (int i = 0; i < numVertices; i++) {
        graph->adjLists[i] = nullptr;
    }

    return graph;
}

void addEdge(Graph* graph, int src, int dest) {
    // 添加边
    Node* newNode = new Node;
    newNode->vertex = dest;
    newNode->next = graph->adjLists[src];
    graph->adjLists[src] = newNode;

    // 添加邻接点
    newNode = new Node;
    newNode->vertex = src;
    newNode->next = graph->adjLists[dest];
    graph->adjLists[dest] = newNode;
}

void increaseMaxLength(Graph* graph, int newMaxLength) {
    Node** newAdjLists = new Node*[newMaxLength];
    for (int i = 0; i < newMaxLength; i++) {
        if (i < graph->numVertices) {
            newAdjLists[i] = graph->adjLists[i];
        } else {
            newAdjLists[i] = nullptr;
        }
    }

    delete[] graph->adjLists;
    graph->adjLists = newAdjLists;
    graph->numVertices = newMaxLength;
}