双向循环链表编写简单学生信息管理系统（C语言）

题目要求
1：要求有登陆功能
2：成员信息：学号，语数外成绩，账号，密码，性别，身份（老师还是学生），以及地址
3：老师和学生都可以修改自己的密码
4：老师可以增加或者删除学生
5：学生只可以查看自己的成绩
6：老师可以查看所有学生的成绩，以及修改本科的成绩

#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h>
#include<string.h>
typedef struct node
{
	int id_num;//teacher or student's number
	char status;//teacher : t , student : s
	int chinese;
	int math;
	int English;
	int passwd;
	char address[64];
	char sex;//man : m , women : w
	struct node *next;
}*listnode;

listnode listnode_init()
{
	listnode head = malloc(sizeof(struct node)); //申请头结点空间
	if(head == NULL)
	{
		perror("list init error");
		return NULL;
	}
	head->next = NULL;
	return head;//返回头结点地址
}

void data_init(listnode newnode ,int id_num,char status,int chinese,int math ,int English , int passwd,char * address,char sex)
{
	newnode->id_num = id_num;
	newnode->status = status;
	newnode->chinese = chinese;
	newnode->math = math;
	newnode->English = English;
	newnode->passwd = passwd;
	strcpy(newnode->address,address);
	newnode->sex = sex;
}

bool add_node(listnode head,int id_num,char status,int chinese,int math ,int English , int passwd,char * address,char sex)
{
	listnode newnode = malloc(sizeof(struct node));
	if(newnode == NULL)
	{
		perror("malloc newnode error");
		return -1;
	}
	//2、初始化节点数据
    data_init(newnode ,id_num,status,chinese,math ,English,passwd,address,sex);
    	
	//3找到链表尾部
	listnode p = head;
	while(p->next != NULL)  //如果p->next不等于 NULL，证明后面还有节点
	{
		p = p->next;	
	}
	newnode->next = p->next;
	p->next = newnode;	
	printf("尾插法所接入的数据 %d,%c\n", p->next->id_num,p->next->status);
    return 0;
}

listnode search_member_prev(listnode head ,int id_number)
{
	listnode tmp = head ;
	while(tmp->next != NULL)
	{
		if(tmp->next->id_num == id_number)
		{
			return tmp ;
		}	
        tmp = tmp->next;		
	}
	return NULL;
}

//传入头节点，和另一个节点
//函数中输入 id_num 和 passwd,若匹配，返回true
listnode login_in(listnode head,listnode newOne)
{
	int passwdInput,id_num;
	listnode new = head;
	printf("please input your id_num(five Number): ");
	if(scanf("%d",&(id_num)) == 1)
	{
		while(getchar() != '\n');
		listnode tmp = search_member_prev(head,id_num);
	    if(tmp != NULL)
		{
			printf("please input your password :");
			scanf("%d",&passwdInput);
			while(getchar() != '\n');
			if(tmp->next->passwd == passwdInput)
			{
				newOne = tmp;
				return newOne;
			}
		}
	}
	return NULL;
}

int JudgeStuTea(listnode head ,listnode newOne)
{
	printf("1");
	int number = newOne->next->id_num ;
	listnode tmp = search_member_prev(head,number);
	if( tmp->next->status == 't')
	{
		printf("this is a teacher\n");
		return 1;
	}
	else
		return 0;
}

void show_grade(listnode newOne)
{
	printf("                                     %d \n",         newOne->next->id_num);
	printf("                                     chinese : %d\n",newOne->next->chinese);
	printf("                                     math    : %d\n",newOne->next->math);
	printf("                                     English : %d\n\n",newOne->next->English);
}
//修改密码
bool alter_passwd(listnode newOne)
{
	char Judge;
	int passwd;
	printf("your password : %d\n",newOne->next->passwd);
	printf("You are sure about changing Your pasword ? y/n : \n");
    scanf("%c",&Judge);
	while(getchar()!='\n');
	if(Judge == 'y')
	{
		printf("please input your new password :\n");
		scanf("%d",&passwd);
		newOne->next->passwd = passwd;
		printf("%d\n",newOne->next->passwd);
	    return true;
	}
	else
	{
		printf("don't waste my time , bitch !\n");
		return false;
	}
}

//学生操作
void StuMove(listnode head , listnode newOne)
{
	int numberOption;
	while(1)
	{
		printf(" hello ，%d \n",newOne->next->id_num);
		printf(" press 0 : show your all grade \n\n");
		printf(" press 1 : alter your passwd \n\n\n");
		printf(" press 2 : exit\n\n");
		printf(" Your option : \n");
		scanf("%d",&numberOption);
		while(getchar() != '\n');
		switch(numberOption)
		{
			case 0:
			    show_grade(newOne);
				break;
			case 1:
			    alter_passwd(newOne);
				break;
			case 2:
			    return;
		}
	}
}

//打印所有的成员信息
void show_all(listnode head)
{
	listnode tmp = head;
	while(tmp->next != NULL)
	{
		printf("\tI\tS\tC\tM\tE\tA\t\tSEX\n\n");
		printf("\t%d\t%c\t%d\t%d\t%d\t%s\t%c\t\n\n",tmp->next->id_num,tmp->next->status,tmp->next->chinese,tmp->next->math ,tmp->next->English ,tmp->next->address,tmp->next->sex);
	    tmp = tmp->next;
	}
}

listnode add_grades(listnode head)
{
	listnode tmp = head;
	char addressInput[20];
	
	while(tmp->next != NULL)
	{
		tmp = tmp->next;
	}
	listnode new  = malloc(sizeof(struct node));
	printf("\n\n");
	printf("please input the student 's id : ");
	scanf("%d",&(new->id_num));
	while(getchar() != '\n');
	printf("\n\n");
	new->status = 's';
	printf("please input the student 's chinese : ");
	scanf("%d",&(new->id_num));
	while(getchar() != '\n');
	printf("\n\n");
	printf("please input the student 's math : ");
	scanf("%d",&(new->math));
	while(getchar() != '\n');
	printf("\n\n");
	printf("please input the student 's English : ");
	scanf("%d",&(new->English));
	while(getchar() != '\n');
	printf("\n\n");
	printf("please input the student 's passwd : ");
	scanf("%d",&(new->passwd));
	while(getchar() != '\n');
	printf("\n\n");
	printf("please input the student 's address : ");
	gets(addressInput);
	strcpy(new->address,addressInput);
	printf("\n\n");
	printf("please input the student 's sex : ");
	scanf("%c",&(new->sex));
	while(getchar() != '\n');
	tmp->next = new;
	show_all(head);
	return head;
}

//修改学生信息
bool alter_grades(listnode head,listnode newOne)
{
	int id_num,grade,subject,judgeStu,teaSubject = 0;
	printf("please input the student's id_num :");
    scanf("%d",&id_num);
	while(getchar() != '\n');
	listnode tmp = search_member_prev(head ,id_num);
	//根据id_num在学生列表中匹配学生，若匹配成功，且该id_num不是一个老师 tmp->next->status != 't'
	//则进行下一步操作
	if( ( tmp != NULL ) && (tmp->next->status != 't'))
	{
		printf("is he this guy ?(y:1,n:0)\n");
		show_grade(tmp);
		scanf("%d",&judgeStu);
		while(getchar()!='\n');
		if(judgeStu == 1)
		{
			//这里匹配登陆账号老师是教哪一科的，从而修改具体学生哪一科的成绩
			if(newOne->next->math == -1)
			{
				printf(" how much about math : ");
				scanf("%d",&(tmp->next->math));
				show_grade(tmp);
				return true;
			}
			else
			    if(newOne->next->chinese == -1)
			{
				printf(" how much about chinese : ");
				scanf("%d",&(tmp->next->chinese));
				show_grade(tmp);
				return true;
			}
			else 
				if(newOne->next->English == -1)
			{
				printf(" how much about English : ");
				scanf("%d",&(tmp->next->English));
			    show_grade(tmp);
				return true;
			}
				
		}
	}
	return false;
	
}

//学生删除操作 参数：一个listnode 的头节点
void student_delete(listnode head)
{
	int id_number,judgeStu;
	listnode tmp = head;
	listnode disap;
	printf("who , delete :");
	scanf("%d",&id_number);
	//根据输入寻找学生，
	tmp = search_member_prev(head ,id_number);
	if(tmp != NULL)
	{
		printf("is he this guy ?(y:1,n:0)\n");
		show_grade(tmp);
		scanf("%d",&judgeStu);
		if(judgeStu == 1)
		{
			disap = tmp->next;
			tmp->next = tmp->next->next;
			free(disap);	
			show_all(head);
			printf("delete student successfully");
		}
		else
		{
			printf("delete failed");
		}
	}
}


//老师操作选项
//根据输入选择老师可以进行的功能
void TeaMove(listnode head,listnode newOne)
{
	int options;
	while(1)
	{
		printf(" welcome , %d",newOne->next->id_num);
		printf(" press 0 : change your passwd\n");
		printf(" press 1 : show the all grades\n");
		printf(" press 2 : alter one student's grades\n");
		printf(" press 3 : delete one student\n");
		printf(" press 4 : add one student\n");
		printf(" press 5 : exit\n\n");
		scanf("%d",&options);
		while(getchar()!= '\n');
			switch(options)
			{
				case 0:
					alter_passwd(newOne);
					break;
				case 1:
					show_all(head);
					break;
				case 2:
					alter_grades(head,newOne);
					break;
				case 3:
					student_delete(head);
					break;
				case 4:
				    head = add_grades(head);
					break;
				case 5:
					return;
			}
		}
}


int main()
{
	//先插入几个学生和老师的信息
	listnode head = listnode_init();
	add_node(head,20161,'t',-1,0,0,123456,"hubeijinghzou",'w');
	add_node(head,20162,'t',0,-1,0,123457,"hubeiwuhan",'m');
	add_node(head,20163,'t',0,0,-1,123458,"hubeixiaogan",'m');
	add_node(head,20164,'s',59,60,61,123459,"hubeijingzhou",'w');
	add_node(head,20165,'s',79,73,77,123450,"hubeijingzhou",'m');
	add_node(head,20166,'s',99,83,87,223450,"hubeijingzhou",'m');
	//验证登陆信息
	listnode newOne = head->next;
	while(1)
	{
		newOne = login_in(head,newOne);
		if(newOne != NULL)
			break;
	}
	//欢迎界面
	printf("welcome to zhangke's school info manage system :\n\n");
	//进行判断，如果是老师，进入 TeaMove
	//如果是学生，进入StuMove
	if( JudgeStuTea(head,newOne) == 1 )
		TeaMove(head,newOne);
	else
		StuMove(head,newOne);
	
}

思路：
1 登陆：我们需要实现登陆功能，我的做法是程序运行时，我先初始化链表，然后插入几个成员信息，包括学生和老师的，（这在主函数的 add_node中可以看到插入了6个成员），你也可以改变思路：初始化链表之后，先进行 add_grades() (即添加成员，再进行登陆程序)，
2 老师：在老师的设定上，我采取了这样的方法，老师没有语数外成绩，教哪一科就将哪一科的成绩设定为-1，登陆监测到是老师就进行Tea_move,然后一个死循环，中间加switch(),对输入的功能选项进行选择，这里，老师查看成绩时，调用的是show_all
3 学生没什么好说的，只有查看成绩时，调用show_grades
4,链表这一块，掌握最基本的增删改查就可以了，然后进行一些练习，在调试程序的时候多加一些priintf();才能更好的查看错误以及程序的运行情况，否则，程序运行报错只有一个段错误，真的惨