c - C-中止指向结构组件(类型指针)的指针的重新分配(核心已转储)

我想对图形进行编程，但是在添加顶点时遇到问题。当我想重新分配内存时，程序停止，控制台仅显示“ aborted（核心转储）”。

这是我的代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

struct Graph
{
    int VertexCounter;
    struct Vertices *vertex;
    struct Edge **adjMat;
}MyGraph;

struct Vertices
{
    int id;
    char name[15];
    float xPos;
    float yPos;
};

struct Edge
{
    int id;
    struct Vertices *start;
    struct Vertices *end;
};


//Initializing a graph with memory for one Vertex and one 1x1 adjecency Matrix but setting the number of Vertices to zero
void initGraph(struct Graph *graph)
{
    graph = (struct Graph *) calloc(1, sizeof(struct Graph));
    graph->vertex = (struct Vertices *) calloc(1, sizeof(struct Vertices));
    graph->adjMat = (struct Edge **) calloc(1, sizeof(struct Edge *));
    *(graph->adjMat) = (struct Edge *) calloc(1, sizeof(struct Edge));

    graph->VertexCounter = 0;
    printf("Number of Vertices: %d\n", graph->VertexCounter);

}

//printing the number of Vertices
void test(struct Graph *graph)
{
    printf("Number of Vertices: %d\n", (*graph).VertexCounter);
}


//Reallocating the memory for an additional Vertex.
//I multiply the VertexCounter - 1 because the struct Graph contains space for one pointer of the type (struct Vertices *)
void addVertex(struct Graph *graph)
{
    graph->VertexCounter++;
    graph = (struct Graph *) realloc(graph, sizeof(struct Graph) +
                            (graph->VertexCounter - 1) * sizeof(struct Vertices));

}


int main()
{
    struct Graph *graphPointer;
    graphPointer = &MyGraph;
    initGraph(graphPointer);
    test(graphPointer);
    addVertex(graphPointer);
    test(graphPointer);
    return 0;
}

输出：

顶点数：0

顶点数：0

中止（核心已弃用）

因此，函数addVertex（struct Graph *）不起作用。

我尚未包括新Edge的重新分配。

我该如何解决？

更新：

void addVertex(struct Graph **graph)
{
    (*graph)->VertexCounter++;
    *graph = realloc(*graph, sizeof(struct Graph) +
                ((*graph)->VertexCounter - 1) * sizeof(struct Vertices));

}


int main()
{
    struct Graph *graphPointer;
    graphPointer = &MyGraph;
    initGraph(graphPointer);
    test(graphPointer);
    addVertex(&graphPointer);
    test(graphPointer);
    return 0;
}

这将返回与以前相同的输出

更新2：

void initGraph(struct Graph **graph)
{
    (*graph) = (struct Graph *) calloc(1, sizeof(struct Graph *));
    (*graph)->vertex = (struct Vertices *) calloc(1, sizeof(struct Vertices));
    (*graph)->adjMat = (struct Edge **) calloc(1, sizeof(struct Edge *));
    *((*graph)->adjMat) = (struct Edge *) calloc(1, sizeof(struct Edge));

    (*graph)->VertexCounter = 0;
    printf("Number of Vertices: %d\n", (*graph)->VertexCounter);

}

//printing the number of Vertices
void test(struct Graph *graph)
{
    printf("Number of Vertices: %d\n", (*graph).VertexCounter);
}


//Reallocating the memory for an additional Vertex.
//I multiply the VertexCounter - 1 because the struct Graph contains space for one pointer of the type (struct Vertices *)
void addVertex(struct Graph **graph)
{

    (*graph)->VertexCounter++;

    void *temp = realloc(temp, sizeof(struct Graph *));
    *graph = temp;

    if(graph == NULL)
        printf("Realloc failed");
}


int main()
{
    struct Graph *graphPointer;
    graphPointer = &MyGraph;
    initGraph(&graphPointer);
    test(graphPointer);
    addVertex(&graphPointer);
    test(graphPointer);
    return 0;
}

我更改了initGraph和addVertex，但输出不会更改。

最佳答案

如以上注释中所指出的，您需要跟踪更改时间，或者可以更改graphPointer。例如，每次调用realloc时，系统可能会被迫移动您的结构，并返回指向新分配的新指针。再次指出，例如，在addVertex的末尾将丢弃此新指针。如果要更改函数中的指针，就像其他任何“按引用调用”参数一样，请将指针传递给它。 （如果您对类型完全严格，只有在确定需要进行类型转换时，编译器才能提供帮助。）

您真正需要做的另一件事是检查呼叫的返回值。有时您认为调用有效，但无效，并且由于参数错误而总是返回NULL。无论哪种方式，您都不希望您的程序在将来某个时候崩溃而没有任何原因的提示。因此，例如，如果重新分配失败，则至少打印该重新分配失败并退出。