学生系统最新修改.txt

来自「一个不错的程序学生管理系统, 有各程序的输入.及其各种功能」· 文本 代码 · 共 437 行

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define LEN sizeof (struct stu)

struct stu   
{
	char num[10];
	float score[3];
	struct stu *next;
};

struct stu *creat(int n)          //创建链表
{
	struct stu *head,*pf,*pb;
	int i;
	
	for(i = 0;i<n;i++)
	{ 
		pb=(struct stu *)malloc(LEN); 
		if(pb == NULL)
		{
			printf("error!");
			exit(0);
		}
		
		printf("input Number:");
		scanf("%s",pb->num);
		printf("input score:\n");
		printf("Chinese:");
		scanf("%f",&pb->score[0]);
		printf("Math:");
		scanf("%f",&pb->score[1]);
		printf("English:");
		scanf("%f",&pb->score[2]);
		
		if(i==0)
			pf = head = pb;    
		else 
			pf->next = pb;  
		pb ->next = NULL;
		pf = pb;
	}
	return(head);
}

void printlist(struct stu *head)    //打印链表里的数据
{
	struct stu *p;
	int i = 0;
	
	if(head == NULL)
		printf("NULL");
	p = head;
	while(p != NULL)
	{
		printf("Number:%s\n   ",p->num);
	    printf("Chinese:%g  Math:%g  English:%g\n",p->score[0],p->score[1],p->score[2]);
		p = p -> next;
	}	 
	printf("\n");
}

struct stu *dellist(struct stu *head,char *num)       //删除节点做法1
{
	struct stu *front,*cursor;

	cursor = head;
	while(cursor != NULL && strcmp(cursor->num,num) != 0)    //找到删除点，首地址为cursor
	{
		front = cursor;
		cursor = cursor-> next; 
	}
	if(cursor != NULL)
	{
		if(head == cursor)
			head = cursor->next;
		else
			front->next = cursor->next;         //删除节点，并释放内存
		free(cursor);
	}
	return (head);
}

struct stu *insert(struct stu *head)    //插入节点
{
	struct stu *pf,*pb,*newone,*pi;
	
	pb = head;
	newone = (struct stu *)malloc(LEN);
	
	printf("请输入要插入的学生的Number:");   
	scanf("%s",newone->num);
	printf("请输入要插入的学生的Score:\n");
	printf("Chinese:");
	scanf("%f",&newone->score[0]);
	printf("Math:");
	scanf("%f",&newone->score[1]);
	printf("English:");
	scanf("%f",&newone->score[2]);
	
	pi = newone;
	if(head == NULL)   
	{
		head = pi;
		pi->next = NULL;
	}
	else
	{
		while(strcmp(pi->num,pb->num) < 0 && (pb->next != NULL))
		{
			pf = pb;
			pb = pb->next; 
		}                     //找插入位置
		if(strcmp(pi->num,pb->num) >= 0)
		{
			if(head == pb)
				head = pi;    //在第一结点之前插入
			else 
				pf ->next = pi;    //在其它位置插入
			pi->next = pb; 
		}
		else
		{
			pb->next = pi;
			pi->next = NULL;
		}                      //在表末插入
	}
	return head;
}

struct stu *paixu(struct stu *head,int i)  //将链表按学生学号从小到大排列
{
	struct stu *pb,*pf,*p1,*p2,*p3,*p;

	p3 = pb = pf = head;
	for(;pf->next != NULL;pf = pf->next)
	{
		p1 = pb = pf;
		while(pb->next != NULL)//选出最大number的节点地址
		{
			p2 = pb;
			pb = pb->next;
			if(strlen(pf->num) == strlen(pb->num) && strcmp(pf->num,pb->num) > 0)
			{
				p = p2; //用p存放pf的前一个指针地址
				pf = pb;//用pf存放number大的指针
			}
			if(strlen(pf->num) > strlen(pb->num))
			{
				p = p2; //用p存放pf的前一个指针地址
				pf = pb;//用pf存放number大的指针
			}
		}
	
		if(pf != p1)
		{	
			p->next = pf->next;
			pf->next = p1;
			if(i != 1)
				p3->next = pf;
			p3 = pf; //p3为每次for循环前一次的pf
		}
		if(i == 1)    //返回排序好的链表的头指针
			goto end;
	}
end:
	return pf;
}

struct stu *paixu2(struct stu *head,int i,int j)  //将链表按学生学号从小到大排列
{
	struct stu *pb,*pf,*p1,*p2,*p3,*p;

	p3 = pb = pf = head;
	for(;pf->next != NULL;pf = pf->next)
	{
		p1 = pb = pf;
		while(pb->next != NULL)//选出最大number的节点地址
		{
			p2 = pb;
			pb = pb->next;
			if(pf->score[j - 1] > pb->score[j - 1])
			{
				p = p2; //用p存放pf的前一个指针地址
				pf = pb;//用pf存放number大的指针
			}
		}
	
		if(pf != p1)
		{	
			p->next = pf->next;
			pf->next = p1;
			if(i != 1)
				p3->next = pf;
			p3 = pf; //p3为每次for循环前一次的pf
		}
		if(i == 1)    //返回排序好的链表的头指针
			goto end;
	}
end:
	return pf;
}

struct stu *chmax(struct stu *head)
{
	struct stu *pb,*pf,*p1;

	pb = pf = head;
	while(pb->next != NULL)//选出最小number的节点地址
		{
			p1 = pb;
			pb = pb->next;
			if(pf->score[0] < pb->score[0])
				pf = pb;//用pf存放number小的指针
		}
	return pf;
}

struct stu *mtmax(struct stu *head)
{
	struct stu *pb,*pf,*p1;

	pb = pf = head;
	while(pb->next != NULL)//选出最大number的节点地址
		{
			p1 = pb;
			pb = pb->next;
			if(pf->score[1] < pb->score[1])
				pf = pb;  //用pf存放number大的指针
		}
	return pf;
}

struct stu *engmax(struct stu *head)
{
	struct stu *pb,*pf,*p1;

	pb = pf = head;
	while(pb->next != NULL)  //选出最大number的节点地址
		{
			p1 = pb;
			pb = pb->next;
			if(pf->score[2] < pb->score[2])
				pf = pb;  //用pf存放number大的指针
		}
	return pf;
}

struct stu *lookup(struct stu *head)     //按学号查找学生
{
	char a[10] = {"0"};
	int i,j = 0;

	printf("请输入需查找学生的学号：");
	scanf("%s",a);
	while(head != NULL)
	{
		for(i = 0;a[i] != 0 || head->num[i] != 0;i++)
		{
			if(a[i] == head->num[i])
				j++;
		}
		if(i == j)
			return head;
		else
			head = head->next;	
	}
	if(head == NULL && i != j)
		return head;
}

void prtamong(struct stu *head,int i)           //打印处于某个分数段的学生信息
{
	float min,max;
	struct stu *p;

	p = head;
	printf("请输入所要打印分数段的最低分数：");
	scanf("%f",&min);
	printf("请输入所要打印分数段的最高分数：");
	scanf("%f",&max);
	printf("分数处于%g到%g的学生为:\n",min,max);
	while(p != NULL)
	{
		if(min <= p->score[i] && max >= p->score[i])
			printf("Number: %s Score: %g\n",p->num,p->score[i]);
		p = p->next; 
	}
}

double average(struct stu *head,int i)       //求平均值
{
	int j = 0;
	double avrg = 0;
	struct stu *p;

	p = head;
	while(p != NULL)
	{
		avrg += p->score[i];
		j++;
		p = p->next;
	}
	return (avrg / j);
}

void file(struct stu *head)       //将学生数据存入文件中
{
	FILE *ff;
	struct stu *pp;

	pp = head;
	if((ff = fopen("stu_list.text","w+")) == NULL)
	{
		printf("打开错误!");
		getchar();
		exit(1);
	}
	while(pp != NULL)
	{
		fprintf(ff,"Number:%s\n Chinese:%g Math:%g English:%g\n",pp->num,pp->score[0],pp->score[1],pp->score[2]);
		pp = pp->next;
	}
	fclose(ff);
}

void main()
{
	int n,s,x;
	char m[10];
	struct stu *head,*head1,*p,*chmax1,*mtmax1,*engmax1,*lookup1;

	printf("*********************************\n");
	printf("      欢迎进入学生管理系统\n");
	printf("*********************************\n");
	
    
	printf("为创建一个学生系统请输入学生个数:\n");        //创建链表
	scanf("%d",&n);
	head = creat(n);
	printf("\n您输入的学生情况如下：\n");
    printlist(head);
	file(head);
	p = head;

	printf("*********************************\n");
	printf("      (1)排列顺序(按学号)\n");
	printf("      (2)查找学生\n");
	printf("      (3)插入学生\n");
	printf("      (4)删除学生\n");
	printf("      (5)某分数段的学生\n");
	printf("      (6)平均成绩\n");
	printf("      (7)某科的最高成绩\n");
	printf("      (8)排列某个科目的成绩\n");
	printf("      (9)打印学生信息\n");
	printf("      (10)将学生数据存入stu_list.text\n");
	printf("*********************************\n");
while(1)
{
	head = p;
	printf("请输入你想进行的功能：");
	scanf("%d",&x);
	switch(x)
	{
	    case 1:	
		    printf("按Number从大到小排列后\n");
			head = paixu(head,1);
	        head1 = paixu(head,2);
	        printlist(head);
			p = head;
			file(head);break;
		case 2: 
		    lookup1 = lookup(head);
		    if(lookup1 != NULL)
		        printf("Number:%s\n  Chinese:%g  Math:%g  English:%g\n",lookup1->num,lookup1->score[0],lookup1->score[1],lookup1->score[2]);
			else
		        printf("该学生不存在!\n"); break;
		case 3:
			head = insert(head);
	        printlist(head);
			p = head;
			file(head);break;	
		case 4:	
		    printf("请输入要删除的学生的Number:");     //输入要删除的学生num，并把对应链表删除
	        scanf("%s",&m);
	        head = dellist(head,m);
	        printlist(head);
		    p = head;
			file(head);break;
		case 5:
			printf("按序号输入科目(1)Chinese(2)Math(3)English:");
	        scanf("%d",&s);
            prtamong(head,s - 1);break;
		case 6:
		    printf("按序号输入科目(1)Chinese(2)Math(3)English:");
	        scanf("%d",&s);
         	printf("平均成绩为：%g\n\n",average(head,s - 1));break;
		case 7:
			printf("按序号输入科目(1)Chinese(2)Math(3)English:");
            scanf("%d",&s);
			if(s == 1)
			{
				chmax1 = chmax(head);
				printf("Number:%s   ",chmax1->num);
	            printf("Chinese:%g\n",chmax1->score[0]);
			}
			if(s == 2)
			{
				mtmax1 = mtmax(head);
				printf("Number:%s   ",mtmax1->num);
	            printf("Math:%g\n",mtmax1->score[1]);
			}
			if(s == 3)
			{
				engmax1 = engmax(head);
				printf("Number:%s   ",engmax1->num);
	            printf("English:%g\n",engmax1->score[2]);
			}break;
		case 8:
			printf("请输入要排序的科目：(1)Chinese(2)Math(3)English:");
			scanf("%d",&s);
			head = paixu2(head,1,s);
	        head1 = paixu2(head,2,s);
	        printlist(head);
			p = head;
			file(head);break;
		case 9:
			printlist(head);break;
		case 10:
			file(head);
			printf("学生数据已经存入stu_list.text中\n");break;
	    default:exit(0);
	}
}
}