如何在不更改原始链接的情况下推进链接列表的副本

Question

So my question is, how can I advance in a copy of a linked list without changing the original list. I kinda understand why this happens I just don't know a way to make it not happen.

This is what I've done and when I call another function that uses these lists they don't exist.

  typedef struct _edgeList
    {
        int target;
        char* tCity;
        char* country;
        int population;
        float weight;
        struct _edgeList *next;
    } EdgeList;

    typedef struct _collisionList
    {
        int id;
        char *city;
        char* country;
        int population;
        EdgeList *edges;
        struct _collisionList *next;
    } CollList;

    void CityWithMostTargets(CollList** hash)
{
    CollList** aux = hash;
    int i = 0;
    int edges = 0;
    int major = 0;
    char* city;

    for(i = 0; i < HASH_SIZE; i++)
    {
        while(aux[i])
        {
            if(aux[i]->edges)
            {
                edges = CountEdges(hash[i]->edges);
            }

            if(edges > major)
            {
                major = edges;
                city = strdup(hash[i]->city);
            }

            if(!aux[i]->next)
                break;

            aux[i] = aux[i]->next;
        }
    }
    aux = hash; 

    printf("City: %s\nNumber of edges: %d", city, major);
    getchar();
}

Answer 1

You can define another variable to hold the value of aux[i] that you want to work with.

for(i = 0; i < HASH_SIZE; i++)
{
    CollList* a = aux[i];
    while (a)
    {
        // etc.

and replace the other uses of aux[i] within that loop to use a .