重写结构体嵌套一级指针老师和二级指针学生的代码
//结构体类型，每个导师有三个学生
typedef struct Teacher
{
char *tName; //导师
char **stu; //三个学生
int age;
}Teacher;
//在createTeacher中分配空间
int createTeacher(Teacher **p/*out*/, int n1, int n2);
//给成员赋值
void initTeacher(Teacher *p, int n1, int n2);
//打印结构体成员信息
void printTeacher(Teacher *p, int n1, int n2);
//根据导师名字排序, 降序
void sortTeacher(Teacher *p, int n);
//释放空间，在函数内部把p赋值为NULL
void freeTeacher(Teacher **p, int n1, int n2);
int main(void)
{
int ret = 0;
int n1 = 3; //导师个数
int n2 = 3; //学生
Teacher *p = NULL;
ret = createTeacher(&p, n1, n2);
if (ret != 0)
{
printf("createTeacher err:%d\n", ret);
return ret;
}
initTeacher(p, n1, n2); //给成员赋值
//打印成员，排序前
printf("排序前：\n");
printTeacher(p, n1, n2);
//根据导师名字排序, 降序
sortTeacher(p, n1);
//打印成员，排序后
printf("\n排序后：\n");
printTeacher(p, n1, n2);
//释放空间，在函数内部把p赋值为NULL
freeTeacher(&p, n1, n2);
return 0;
}
#pragma warning(disable:4996)
#include<stdio.h>
#include<stdlib.h>
#include<string.h> typedef struct Teacher
{
char *tName; //导师
char **stu; //三个学生
int age;
}Teacher; //在createTeacher中分配空间
int createTeacher(Teacher **p/*out*/, int n1, int n2) {
if (p == NULL) { return -;
}
int i = ;
int j = ;
Teacher *tmp = NULL;//Teacher tmp[3]
tmp =(Teacher*)malloc(n1 * sizeof(Teacher));
if (tmp == NULL) {
return -;
}
for (i = ; i < n1; i++) {
//导师
tmp[i].tName = (char *)malloc(); //学生
char **s = (char **)malloc(n2 * sizeof(char *));
for (j = ; j < n2; j++) {
s[j] = (char *)malloc(); }
//直接赋值
tmp[i].stu = s;
} //间接赋值是指针存在的最大意义
*p = tmp; return ;
} //给成员赋值
void initTeacher(Teacher *p, int n1, int n2) {
if (p == NULL) {
return;
}
int i = ;
int j = ;
char buf[];
for (i = ; i < n1; i++) {
//导师名字
sprintf(buf, "teacher%d%d%d", i, i, i);
strcpy(p[i].tName, buf); //年龄
p[i].age = + * i; //n2学生
for (j = ; j < n2; j++) {
sprintf(buf, "stu%d%d%d%d", i, i, j, j);
strcpy(p[i].stu[j], buf);
}
}
} //打印结构体成员信息
void printTeacher(Teacher *p, int n1, int n2) {
if (p == NULL)
return;
int i = ;
int j = ; for (i = ; i < n1; i++) {
//导师名字
//年龄
printf("%s[%d]\n", p[i].tName, p[i].age);
//学生
for (j = ; j < n2; j++) {
printf("\t%s", p[i].stu[j]);
}
printf("\n");
}
} //根据导师名字排序, 降序
void sortTeacher(Teacher *p, int n) {
if (p == NULL) {
return;
}
int i = ;
int j = ;
Teacher tmp; for (i = ; i < n-; ++i) {
for (j = i + ; j < n; j++) {
if (strcmp(p[i].tName, p[j].tName) < ) {
tmp = p[i];
p[i] = p[j];
p[j] = tmp;
}
}
}
} //释放空间，在函数内部把p赋值为NULL
void freeTeacher(Teacher **p, int n1, int n2) {
if (p == NULL) {
return;
}
Teacher *tmp = *p; int i = ;
int j = ;
for (i = ; i < n1; i++) {
//可以释放导师
if (tmp[i].tName != NULL) {
free(tmp[i].tName);
tmp[i].tName = NULL;
} //学生
for (j = ; j < n2; j++) {
if (tmp[i].stu[j] != NULL) {
free(tmp[i].stu[j]);
tmp[i].stu[j] = NULL;
}
}
if (tmp[i].stu != NULL) {
free(tmp[i].stu);
}
}
if (tmp != NULL) {
free(tmp);
*p = NULL;
}
} int main(void)
{
int ret = ;
int n1 = ; //导师个数
int n2 = ; //学生
Teacher *p = NULL; ret = createTeacher(&p, n1, n2);
if (ret != )
{
printf("createTeacher err:%d\n", ret);
return ret;
} initTeacher(p, n1, n2); //给成员赋值 //打印成员，排序前
printf("排序前：\n");
printTeacher(p, n1, n2); //根据导师名字排序, 降序
sortTeacher(p, n1); //打印成员，排序后
printf("\n排序后：\n");
printTeacher(p, n1, n2); //释放空间，在函数内部把p赋值为NULL
freeTeacher(&p, n1, n2); return ;
}