解放出来的动态结构阵列的存储

Question

其我再次：d

我有以下结构：

typedef struct 
{ 
    int day, month, year; 
}date; 

typedef struct 
{ 
    char name[15]; 
    date birth; 
    int courses; 
    int *grades; 
}student; 

那我该怎么分配的内存每个数组：

printf("What is the number of students?\n"); 
    scanf("%d", &size); //asking for size from user and creating 'size' number of structs 
    for (i = 0; i < size; i++) { 
     pData[i] = malloc(sizeof(student) * size); 
    } 
    ........ //initializing char and birth 
    for (i = 0; i < size; i++) { 
     printf("\nPlease enter number of courses of student #%d:\n", i+1); 
     scanf("%d", &pData[i]->courses); //allocating memory for array of grades for each student (i) 
     pData[i]->grades = (int*)malloc(sizeof(int)*pData[i]->courses); 
    } 
    for (j = 0; j < size; j++) { 
     for (i = 0; i < pData[j]->courses; i++) { 
      printf("\nPlease enter grades of student #%d in course #%d\n", j+1, i+1); 
      scanf("%d", &pData[j]->grades[i]); 
     } //entering grades of each student 

现在我有麻烦释放内存...我已经尝试了很多方法，但程序每次都以错误结尾..

我试过这个方法：

for (i = 0; i < size; i++) { 
     free(pData[i].grades); 
    } 
    free(pData); 
    pData = NULL; 

然而，我仍然得到错误...

编辑：那我就veriable的pData如何声明：

student* pData = NULL; 

那是初始化函数阵列：

int initialize(student**); 

多数民众赞成我是如何发送pData功能：

size = initialize(&pData); //the function is suppose to return the size of the array. 

Answer 1

您没有正确地为pData分配空间。你这样做一次，并将其分配到*pData，而不是pData[i]。你有一个指针指针，而不是指针数组。

printf("What is the number of students?\n"); 
scanf("%d", &size); //asking for size from user and creating 'size' number of structs 
*pData = malloc(sizeof(student) * size); 

然后您需要在读取数据时正确引用它。

for (i = 0; i < size; i++) { 
    printf("\nPlease enter number of courses of student #%d:\n", i+1); 
    scanf("%d", &(*pData)[i].courses); //allocating memory for array of grades for each student (i) 
    (*pData)[i].grades = (int*)malloc(sizeof(int)*(*pData)[i].courses); 
} 
for (j = 0; j < size; j++) { 
    for (i = 0; i < (*pData)[j].courses; i++) { 
     printf("\nPlease enter grades of student #%d in course #%d\n", j+1, i+1); 
     scanf("%d", &(*pData)[j].grades[i]); 
    } 
} 

编辑：

为了进一步解释pData是如何被使用的语法，这里有相关表述的各部分的数据类型。

  pData: student ** 
     *pData: student * 
    (*pData)[i]: student