编写程序：建立一个学生数据链表，每个节点的信息包括如下内容：学号，姓名，性别年龄专业。对链表做如下处理。输入一个学号（专业），如果链表中的节点包含此学号（专业），则删去该结点。

#include <iostream>
using namespace std;


struct student
{
char name[20];
char s_number[10];
char gender[3];
int age;
char major[10];
struct student* next;
};


student* CREATE_LIST();
int operation(student* head);
int PRINT_LIST(student* head);
student* DROP_F_NUMBER(student* head);
student* DROP_F_MAJOR(student* head);
student* DROP_LIST(student* head);


int main()
{
student* head = CREATE_LIST();
operation(head);
return 0;
}


student*  CREATE_LIST()
{
int number = 0;
student* q = new student, *head = q;


while (1)
{
printf("有多少名学生？\n请输入：");
scanf("%d", &number);
if (number <= 0) printf("\n请输入正确的人数！\n");
else break;
}


for (int n = 0;; n++)
{
printf("---------------------------------------------------\n");
printf("\n请输入学生的姓名：");
scanf("%s", q->name);
printf("\n请输入学生的学号：");
scanf("%s", q->s_number);
printf("\n请输入学生的性别：");
scanf("%s", q->gender);
printf("\n请输入学生的年龄：");
scanf("%d", &q->age);
printf("\n请输入学生的专业：");
scanf("%s", q->major);
if (n == number - 1)
{
q->next = NULL;
break;
}
student* p = new student;
q->next = p;
q = p;
}


return head;
}


int operation(student* head)
{
int x;


while (1)
{
printf("---------------------------------------------------\n");
printf("1.打印所有数据\n2.按照学号删除数据\n3.按照专业删除数据\n4.退出\n");
printf("请输入要操作什么：");
scanf("%d", &x);


switch (x)
{
case 1:
PRINT_LIST(head);
break;
case 2:
head = DROP_F_NUMBER(head);
break;
case 3:
head = DROP_F_MAJOR(head);
break;
case 4:
DROP_LIST(head);
return 0;
default:
printf("请输入正确的选择！\n");
break;
}


}
}


int PRINT_LIST(student* head)
{
if (head == NULL)
{
printf("---------------------------------------------------\n");
printf("没有学生信息！\n");
return 0;
}
printf("---------------------------------------------------\n");
printf("姓名：\t学号：\t\t性别：\t年龄：\t专业：\n");
while (head != NULL)
{
printf("%s\t%s\t%s\t%d\t%s\n",
head->name,
head->s_number,
head->gender,
head->age,
head->major);
head = head->next;
}
return 0;
}


student* DROP_F_NUMBER(student* head)
{
if (head == NULL)
{
printf("---------------------------------------------------\n");
printf("没有学生信息。无法删除！\n");
return 0;
}


student Z, *p = &Z;
char s_number[10];


printf("---------------------------------------------------\n");
printf("请输入要删除的学号：");
scanf("%s", s_number);


for (p->next = head; p->next != NULL; p = p->next)
{
if (strcmp((p->next)->s_number, s_number) == 0)
{
student* q = p->next;
p->next = (p->next)->next;
delete q;
printf("已删除学号为：%s的学生信息。\n", s_number);
break;
}
}


return Z.next;
}


student* DROP_F_MAJOR(student* head)
{
if (head == NULL)
{
printf("---------------------------------------------------\n");
printf("没有学生信息。无法删除！\n");
return 0;
}


student Z, *p = &Z;
int x = 0;
char major[10];


printf("---------------------------------------------------\n");
printf("请输入要删除的专业：");
scanf("%s", major);




for (p->next = head; p->next != NULL;)
{
if (strcmp((p->next)->major, major) == 0)
{
x = 1;
student* q = p->next;
p->next = (p->next)->next;
delete q;
continue;
}
p = p->next;


}
if (x == 1)printf("已删除所有专业为：%s的学生信息。\n", major);
else printf("没有专业为：%s的学生！\n", major);
return Z.next;
}


student* DROP_LIST(student* head)
{
student* p = head;
while (head != NULL)
{
head = head->next;
delete p;
p = head;
}
return 0;
}