反向链接列表（段故障）

Question

My goal is to create a function which performs reverse operation on a List and return the reverse List.

Root --> First element in the List, 
size --> Size of the list, 
str -->  Data (string) in the list and 
next --> Points to next node in the List. 

The problem is that I am getting segmentation fault core dumped.

Please help me to solve this.

Thank's in advance

typedef struct {
    element *root;
    int size;
} list;


typedef struct _element {
    char* str;
    struct _element *next;
} element;



list* reverse_list(list *lst) {
    lst = malloc(sizeof(list));

    element *aux1, *aux2, *aux3;
    aux1 = malloc(sizeof(element));
    aux2 = malloc(sizeof(element));
    aux3 = malloc(sizeof(element));

    aux1 = lst->root;
    aux2 = NULL;

    while (aux1->next != NULL) {
        aux3 = aux1->next;
        aux1->next = aux2;
        aux2 = aux1;
        aux1 = aux3;
    }

    lst->root = aux1;

    return lst;
}

Answer 1

First of all i advice You to learn what is encapsulation. I understand this is a sample but splitting the code into create_list reverse_list destroy_list is a great practice.

The problem is here:

   aux1 = lst->root;
   aux2 = NULL;

You loose pointer to aux1 and aux2. That's a memory leak and it's real easy to track with a debugger like gdb. when while tries to read aux1 it gets an undefined pointer with trash value in it

You also need to read about RAII.