hqs_wyx_student_management/8_link_list.c

#include<stdio.h>
#include<string.h>
#include<stdlib.h> 
#define N 100

struct stu_info
{
	char num[20];
	char cls[20];
	char name[20];
	float math,physics,english,total;	struct stu_info* prev;
	struct stu_info* next;
};

struct stu_info stu[N];
int top=0;
struct stu_info *head=NULL;
struct stu_info *tail=NULL;

void print_menu()
{
	printf("1.input\n");
	printf("2.delete\n");
	printf("3.select\n");
	printf("4.order\n");
	printf("5.output\n");
	printf("6.quit\n");
	printf("please input your option\n");
}

void print()
{
	struct stu_info* p=head;
	while (p!=NULL)
	{
		printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",p->num,p->cls,p->name,p->math,p->physics,p->english,p->total);
		p=p->next;
	}
}
	

void input()
{
	char op[20];
	struct stu_info* p=NULL;
	while(1)
	{
		p=(struct stu_info *)malloc(sizeof(struct stu_info));
		if (head==NULL)
		{
			head=p;
		}
		//p->num = (char *)malloc(sizeof(char) * 20);
		//p->cls = (char *)malloc(sizeof(char) * 20);
		//p->name = (char *)malloc(sizeof(char) * 20);
		printf("Id ");
		scanf("%s",p->num);
		printf("class ");
		scanf("%s",p->cls);
		printf("name ");
		scanf("%s",p->name);
		printf("score1 ");
		scanf("%f",&p->math);
		printf("score2 ");
		scanf("%f",&p->physics);
		printf("score3 ");
		scanf("%f",&p->english);
		p->total=p->math+p->physics+p->english;
		p->prev=tail;
		p->next=NULL;
		if(p!=head) tail->next=p;
		tail=p;
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void del()
{
	struct stu_info* p=head;
	char key[20],op[20];
	while(1)
	{
		p=head;
		scanf("%s",key);
		while(p!=NULL)
		{
			if(strcmp(p->num,key)==0||strcmp(p->name,key)==0)
			{
				if(p==head) head=p->next;
				else (p->prev)->next=p->next; 
				(p->next)->prev=p->prev;
			}
			p=p->next;
		}
		print();
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void slc()
{
	int flag;
	struct stu_info* p=head;
	char key[20],op[20];
	while(1)
	{
		flag=0;p=head;
		scanf("%s",key);
		while(p!=NULL)
		{
			if(strcmp(p->num,key)==0||strcmp(p->cls,key)==0)
			{
				flag=1;
				printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",p->num,p->cls,p->name,p->math,p->physics,p->english,p->total);
			}
			p=p->next;
		}
		if(!flag)
		{
			printf("there is no eligible student\n");
			return;
		}
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void order()
{
	struct stu_info* p=tail;
	struct stu_info* q=head;
	struct stu_info* tmp=NULL;
	while(p!=NULL)
	{
		q=head;
		while(q!=p)
		{
			if(strcmp((q)->cls,(q->next)->cls)==1||strcmp((q)->cls,(q->next)->cls)==0&&((q)->total<(q->next)->total))
			{
				if(p==q->next) p=q;
				if(head==q) head=q->next;
				else (q->prev)->next=q->next;
				if(tail==q->next) tail=q;
				else ((q->next)->next)->prev=q;
				tmp=q->next;
				q->next=tmp->next;
				tmp->prev=q->prev;
				tmp->next=q;
				q->prev=tmp;
			} 
			else q=q->next;
		}
		p=p->prev;
	}
	print();
	return;
}

int main()
{
	int op;
	while(1)
	{
		print_menu();
		scanf("%d",&op);
		switch(op)
		{
			case(1):
				input();
				break;
			case(2):
				del();
				break;
			case(3):
				slc();
				break;
			case(4):
				order();
				break;
			case(5):
				print();
				break;
			case(6):
				return 0;
		}
	}
}