已知自定义结构体类型
typedef struct
{
char name[20];
int math;
int eng;
int db;
}student;
分别用值传递和引用调用两种方式编写函数setzero，实现对学生成绩的清零操作，并在主函数中以正确的方式调用

很急

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

typedef struct
{
    char name[20];
    int math;
    int eng;
    int db;
} student;

student setzero(student stu)
{
    //memset(&stu, 0, sizeof(student));
    stu.math = 0;
    stu.eng = 0;
    stu.db = 0;
    return stu;
}

student *setzero2(student *stu)
{

    //memset(stu, 0, sizeof(student));
    stu->math = 0;
    stu->eng = 0;
    stu->db = 0;
    return stu;
}

int main(void)
{
    student stu = {"AAA",1,2,3};
    printf("%s %d %d %d\n", stu.name, stu.math, stu.eng, stu.db);
    stu = setzero(stu);
    printf("%s %d %d %d\n", stu.name, stu.math, stu.eng, stu.db);
    student stu2 = {"BBB",11,22,33};
    printf("%s %d %d %d\n", stu2.name, stu2.math, stu2.eng, stu2.db);
    setzero2(&stu2);
    printf("%s %d %d %d\n", stu2.name, stu2.math, stu2.eng, stu2.db);
    return 0;
}