PTA學生成績鏈表處理

1.首先創建頭指針並初始化，即頭指針->next=NULL。接着創建鏈表指針，並用頭指針初始化。

2.可用while循環獲取信息，直到檢測到輸入值為0為止。在循環中，給鏈表指針申請新的內存空間，並初始化，同時因節點增加，指針不斷后移。

3.刪除函數，頭節點單拿出來判斷。創建臨時指針保存滿足條件的節點地址，進行刪除操作。

#include<iostream>
using namespace std;

struct stud_node {
 int    num;
 char   name[20];
 int    score;
 struct stud_node* next;
};

struct stud_node* createlist()
{
 stud_node* fujia = new stud_node;/*創建頭指針*/
 fujia->next = NULL;
 stud_node*temp=fujia;/*創建鏈表,指向頭指針*/
 cin >> temp->num;
 while (temp->num)
 {
  cin >> temp->name >> temp->score;
  temp->next = new stud_node;
  temp = temp->next;
  cin >> temp->num;
  temp->next = NULL;
 }
 return fujia;
}
struct stud_node* deletelist(struct stud_node* head, int min_score)
{
 if (head->score < min_score&&head)
 {
  stud_node* deletep = head;
  head = deletep->next;
  delete deletep;
 }
 for (stud_node* shanchu = head; shanchu!=NULL&&shanchu->next!= NULL; shanchu = shanchu->next)
 {
  if(shanchu->next->score<min_score)
  {
      stud_node*deletep = shanchu->next;
   shanchu->next = deletep->next;
   delete deletep;
  }
 }
  return head; 
}

int main()
{
 int min_score;
 struct stud_node* p, * head = NULL;
 head = createlist();
 cin >> min_score;
 head = deletelist(head, min_score);
 for (p = head; p != NULL; p = p->next)
  cout << p->num << " " << p->name << " " << p->score << endl;
 return 0;
}