对于以下图形声明（我无法更改 - 赋值；还有宏，因为我不允许对图形使用 '.' 和 '->' 运算符）
#include <string.h>
#include <stdlib.h>
#define TAG(vp) ((vp)->tag)
#define LABEL(vp) ((vp)->label)
#define EDGE(vp) ((vp)->edge)
typedef struct vertex
{
char tag;
char *label;
struct vertex *edge[1];
}
vertex, *vp;
和这个邻接列表声明（对于这个和所有下一个代码，我可以做任何我想做的事情）
typedef struct adjList
{
vp node;
struct adjList *next;
}
adjList;
我写了一个函数的两个版本，它必须从图中创建邻接表表示。他们都使用此功能创建一个列表。
adjList *createList (vp graph)
{
int i;
adjList *result, *ptr, *ptr2;
if (graph)
{
result = malloc (sizeof (adjList));
result->node = graph;
ptr2 = result;
for (i = 0; EDGE (graph)[i]; ++i)
{
ptr = malloc (sizeof (adjList));
ptr->node = EDGE (graph)[i];
ptr2->next = ptr;
ptr2 = ptr;
}
ptr2->next = NULL;
}
return result;
}
第一个返回一个邻接列表数组（作为双指针），但仅对一个节点及其子节点执行此操作（我还没有弄清楚如何使用此工作函数返回完整表示）
adjList **createLists (vp graph)
{
int i;
adjList **result;
result = malloc (sizeof (adjList *));
result[0] = createList (graph);
for (i = 0; EDGE (graph)[i]; ++i)
{
result = realloc (result, sizeof (adjList *) * (i + 2));
result[i + 1] = createList (EDGE (graph)[i]);
}
result = realloc (result, sizeof (adjList *) * (i + 2));
result[i + 1] = NULL;
return result;
}
第二个产生分段错误。基本上，它创建了一个空列表数组，但使用这个逻辑我会创建完整的表示。
void createListsHelper (adjList **result, vp graph, int *index) /* index stores an index in an array to create there next list */
{
int i;
if (graph)
{
result = realloc (result, sizeof (adjList *) * (*index + 2));
result[*index] = createList (graph);
for (i = 0; EDGE (graph)[i]; ++i)
{
++(*index);
createListsHelper (result, EDGE (graph)[i], index);
}
}
}
adjList **createLists (vp graph)
{
adjList **result = malloc (sizeof (adjList *));
int *index = malloc (sizeof (int));
*index = 0;
createListsHelper (result, graph, index);
result[*index + 1] = NULL;
return result;
}
我怎样才能改变其中之一，使它们能够正常工作。
提前致谢。
注意：我使用以下“主要”来测试它们。
int main()
{
int i;
adjList **list, *ptr;
vp test;
test = malloc (sizeof (vertex) + 4 * sizeof (vp));
LABEL (test) = malloc (sizeof (char) * 2);
LABEL (test)[0] = 'a';
LABEL (test)[1] = '\0';
for (i = 0; i < 3; ++i)
{
EDGE (test)[i] = malloc (sizeof (vertex));
}
LABEL (EDGE (test)[0]) = malloc (sizeof (char) * 2);
LABEL (EDGE (test)[0])[0] = 'b';
LABEL (EDGE (test)[0])[1] = '\0';
LABEL (EDGE (test)[1]) = malloc (sizeof (char) * 2);
LABEL (EDGE (test)[1])[0] = 'c';
LABEL (EDGE (test)[1])[1] = '\0';
LABEL (EDGE (test)[2]) = malloc (sizeof (char) * 2);
LABEL (EDGE (test)[2])[0] = 'd';
LABEL (EDGE (test)[2])[1] = '\0';
EDGE (test)[3] = NULL;
EDGE (EDGE (test)[0])[0] = NULL;
EDGE (EDGE (test)[1])[0] = NULL;
EDGE (EDGE (test)[2])[0] = NULL;
list = createLists2 (test);
for (i = 0; list[i]; ++i)
{
for (ptr = list[i]; ptr; ptr = ptr->next)
{
printf ("%c ", LABEL (ptr->node)[0]);
}
printf ("\n");
}
return 0;
}