c提高第五次作业

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 -1;
    }
    int i = 0;
    int j = 0;
    Teacher *tmp = NULL;//Teacher tmp[3]
    tmp =(Teacher*)malloc(n1 * sizeof(Teacher));
    if (tmp == NULL) {
        return -2;
    }
    for (i = 0; i < n1; i++) {
        //导师
        tmp[i].tName = (char *)malloc(30);


        //学生
        char **s = (char **)malloc(n2 * sizeof(char *));
        for (j = 0; j < n2; j++) {
            s[j] = (char *)malloc(30);

        }
        //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 0;
}

//给成员赋值
void initTeacher(Teacher *p, int n1, int n2) {
    if (p == NULL) {
        return;
    }
    int i = 0;
    int j = 0;
    char buf[30];
    for (i = 0; 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 = 30 + 2 * i;

        //n2学生
        for (j = 0; 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 = 0;
    int j = 0;

    for (i = 0; i < n1; i++) {
        //导师名字
        //年龄
        printf("%s[%d]\n", p[i].tName, p[i].age);
        //学生
        for (j = 0; 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 = 0;
    int j = 0;
    Teacher tmp;

    for (i = 0; i < n-1; ++i) {
        for (j = i + 1; j < n; j++) {
            if (strcmp(p[i].tName, p[j].tName) < 0) {
                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 = 0;
    int j = 0;
    for (i = 0; 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 = 0; 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 = 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;
}

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