Question

这是我的结构和我添加的节点。我的插入功能没问题，但是当我尝试稍后添加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，它什么都没显示。然后当我添加另一个节点时，Course_Student数据以奇怪的方式显示。如何在以后将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于将数据添加到链接列表的功能。

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++){

......什么是n？看起来n可能是一个全局设置为10，用于循环通过cs？如果是这样，那么你的方法并不是最好的。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相同的学生记录中？如果是这样，你应该这样做：

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

请确认您正在尝试实现的目标，然后我或此处的其他人可以帮助您使用正确的算法。

此外，请确保您的缩进正确，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;
    }

Answer 2

您应该使用startPtr_s初始化循环并使用Node_s作为临时变量：

void Select_Course(NodePtr_s *startPtr_s, Course_Student cs[10], int id)
{
  Node_s *current = NULL;
  int i;

  /* iterate on each node in your list */
  for (current = *startPtr_s; current != NULL; current = current->next_s) {
    if (current->s.uID != id) continue;

    /* On each node update your data */
    for (i = 0; i < n; i++) {
      current->s.a[i].crs_code = cs[i].crs_code;
      strcpy(current->s.a[i].name,cs[i].name);
      current->s.a[i].unt = cs[i].unt;
    }
  }
}

链接结构列表 - 如何编辑数据

2 个答案: