结构体中含有结构体指针

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

const int t_length = 2;

int s_index = 5000;

typedef struct Student{
    int id;
    char name[64];
    int age;
}Student;
typedef struct Teacher{
    int id;
    char name[64];
    int age;
    int s_num;
    Student *stu;
}Teacher;

void createTeahcer(Teacher **ppt,int t_num);//为教师数组分配内存

void freeTeacher(Teacher *pt, int t_num); //释放内存

void sortStudent( Student * pt, int num ); //学生数组的排序

void sortTeacher(Teacher *pt, int num); //教师数组的排序

void printTeacher(Teacher *pt, int num); //遍历数组

void createTeahcer(Teacher **ppt,int t_num){

    Teacher *temp;

    temp = (Teacher *)malloc(sizeof(Teacher) * t_num);

    *ppt = temp;

}

void freeTeacher(Teacher *pt, int t_num){
    
    int i;

    if(pt != NULL){

        for (i = 0; i < t_num; ++i){
            if(pt[i].stu != NULL){
                free(pt[i].stu);
                pt[i].stu = NULL;
            }
        }

        free(pt);
    }

    
}


void sortStudent( Student * pt, int num ) {
    
    int i, j;

    Student temp;

    for(i = 0; i < num; ++i){

        for(j = i + 1; j < num; ++j){

            if(pt[j].age < pt[i].age){

                temp = pt[j];
                pt[j] = pt[i];
                pt[i] = temp;

            }
        }

    }
}

void sortTeacher(Teacher *pt, int num){

    int i, j;

    Teacher temp;

    for(i = 0; i < num; ++i){

        for(j = i + 1; j < num; ++j){
        
            if(pt[j].age < pt[i].age){
                
                temp = pt[j];
                pt[j] = pt[i];
                pt[i] = temp;

            }
        }

        sortStudent(pt[i].stu, pt[i].s_num);

    }

}



void printTeacher(Teacher *pt, int num){

    int i, j = 0;

    Student stu;
    printf("\n");
    for(i = 0; i < num; ++i){
        printf("学号：%d 姓名：%s 年龄：%d\n", pt[i].id, pt[i].name, pt[i].age);

        for(j = 0; j < pt[i].s_num; ++j){
            stu = (pt[i].stu)[j];
            printf("第%d位学生 学号：%d 姓名：%s 年龄：%d\n",j + 1, stu.id, stu.name, stu.age);
        }

    }


}

int main(){

    int i, j;

    Teacher *pt = NULL;

    createTeahcer(&pt, t_length);

    for(i = 0; i < t_length; ++i){
        pt[i].id = i + 1002;
        printf("请输入第%d老师位的名字：", i + 1);
        scanf("%s",&(pt[i].name));

        printf("请输入第%d位老师的年龄:", i + 1);
        scanf("%d", &(pt[i].age));
        
        printf("请输入第%d位老师的所带学生的人数:", i + 1);
        scanf("%d", &(pt[i].s_num));

        pt[i].stu = (Student *)malloc(sizeof(Student) * (pt[i].s_num)); //为老师所拥有的学生分配内存

        for( j = 0; j < pt[i].s_num; ++j){
            (pt[i].stu)[j].id = 5000 + s_index++;

            printf("请输入第%d位同学的名字：", j + 1);
            scanf("%s",&((pt[i].stu)[j].name));

            printf("请输入第%d位同学的年龄:", j + 1);
            scanf("%d", &((pt[i].stu)[j].age));
        }

    }
    sortTeacher(pt,t_length);
    printTeacher(pt, t_length);
    freeTeacher(pt, t_length);

    system("pause");
    return 0;
}