方法调用的分段错误

Question

我在尝试调用addEdge(int, int)方法时遇到分段错误。 calling code在下方。有人可以帮忙吗？

    void addEdge(int i, int j) 
{
        if (i >= 0 && j > 0) 
    {
        Node* whereto;
        whereto = linkedAdjacencyList[i];
        if(whereto != NULL) //the segmentation fault occurs here
        {
            while(whereto->adj != NULL)
            {whereto = whereto->adj;}
            whereto->adj = linkedAdjacencyList[j];
        }
        else{linkedAdjacencyList[i]->adj = linkedAdjacencyList[j];}
        whereto = linkedAdjacencyList[j];
        if(whereto != NULL)
        {
            while(whereto->adj != NULL)
            {whereto = whereto->adj;}
            whereto->adj = linkedAdjacencyList[i];
        }
        else{linkedAdjacencyList[j]->adj = linkedAdjacencyList[i];}
            }
    }


std::istream& operator>>(std::istream& in, UndirectedGraph& g)
{
    int numVerticies;
    in >> numVerticies;

    g = UndirectedGraph(numVerticies);
int edges;
in >> edges;
g.edges = edges;
for(int i = 0; i < edges; i++)
{
    int first;
    int second;
    in >> first >> second;
    g.addEdge(first, second);
}

任何想法？

Answer 1

我会说你的'g'对象没有正确实例化。使用'new'创建并使用 - ＆gt;运营商调用addEdge函数。