c - 释放动态结构数组的内存

又是我：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;

我就是这样给每个数组分配内存的：

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

现在我很难释怀。。。我试过很多方法，但每次程序都以错误结束。。
我试过这种方法：

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

但我还是有错误。。。
编辑：这就是我在veriable pData上声明的方式：

student* pData = NULL;

这是初始化数组的函数：

int initialize(student**);

这就是我如何将pData发送到函数：

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

最佳答案

您没有为pData正确分配空间。这样做一次并将其分配给*pData，而不是pData[i]。您有指向指针的指针，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，在读取数据时需要正确引用它。

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：
为了进一步解释如何使用pData的语法，下面是相关表达式的每个部分的数据类型。

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

关于c - 释放动态结构数组的内存，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41749810/