c - 结构链表 - 如何编辑数据

Question

这是我的结构和我添加的节点。我的插入功能没问题，但是当我稍后尝试添加 Course_Student 数据时，通过搜索学生的 uId 并将数据添加到该特定节点；我的列表被删除了，什么也没有显示。然后当我添加另一个节点时，Course_Student 数据以一种奇怪的方式显示。以后如何将 My Course_Student 数据添加到一个特定节点？

typedef struct stdnt Student ;
typedef struct crs_std Course_Student;

struct crs_std{  
    int crs_code;
    char name[20];
    float grade;
    int unt;
};

struct stdnt { 
       char firstname[20];
       char lastname[20];
       Course_Student a[10];
       unsigned long long uID;
       int year;
       float avg;
};

struct Linked_list_Student{

    Student s;
    Node_s *next_s ;

这是我在插入数据后用来向我的链表添加数据的函数。

void Select_Course(NodePtr_s *startPtr_s, Course_Student cs[10], int id){
    int i;
    NodePtr_s prevPtr_s;
    NodePtr_s currPtr_s;
    for(i=0;i<n;i++){

        if((*startPtr_s)->s.uID == id){

            (*startPtr_s)->s.a[i].crs_code = cs[i].crs_code;
            strcpy((*startPtr_s)->s.a[i].name,cs[i].name);
            (*startPtr_s)->s.a[i].unt = cs[i].unt;

        }

        prevPtr_s = (*startPtr_s);
        currPtr_s = (*startPtr_s)->next_s;

        while(currPtr_s != NULL){

            if(currPtr_s->s.uID == id){

                currPtr_s->s.a[i].crs_code = cs[i].crs_code;
                strcpy(currPtr_s->s.a[i].name,cs[i].name);
                currPtr_s->s.a[i].unt = cs[i].unt;

        }

        prevPtr_s = currPtr_s;
        currPtr_s = currPtr_s->next_s;
        }


    }

}

Answer 1

在你的 for 循环中:

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

...n 是什么？看起来 n 可能是全局设置为 10，用于循环 cs？如果是这样，那么您的方法不是最好的。看来你是:

foreach element in cs
    find the correct student record
    add that element from cs to the student record

但听起来 cs 中的所有元素都应该添加到同一个学生记录中？如果是这样，你真的应该这样做:

find the correct student record
foreach element in cs
    add that element to the student record

请确认这是您要实现的目标，然后我或这里的其他人可以帮助您使用正确的算法。

此外，请确保缩进正确，以便人们可以轻松阅读您的代码:

    while(currPtr_s != NULL){

        if(currPtr_s->s.uID == id){

            currPtr_s->s.a[i].crs_code = cs[i].crs_code;
            strcpy(currPtr_s->s.a[i].name,cs[i].name);
            currPtr_s->s.a[i].unt = cs[i].unt;

    }

    prevPtr_s = currPtr_s;
    currPtr_s = currPtr_s->next_s;
    }

应该是

    while(currPtr_s != NULL){

        if(currPtr_s->s.uID == id){

            currPtr_s->s.a[i].crs_code = cs[i].crs_code;
            strcpy(currPtr_s->s.a[i].name,cs[i].name);
            currPtr_s->s.a[i].unt = cs[i].unt;

        }

        prevPtr_s = currPtr_s;
        currPtr_s = currPtr_s->next_s;
    }