041.学生成绩管理程序

Posted 2022-04-29 程序员编程指南

/*
学生成绩管理程序
编制一个统计学生考试分数的管理程序。
设学生成绩已以一个学生一个记录的形式存储在文件中，
每位学生记录包含的信息有：姓名，学号和各门功课的成绩。
程序具有以下几项功能：求出各门课程的总分，平均分，按姓名，
按学号寻找其记录并显示，浏览全部学生成绩和按总分由高到低显示学生信息等。
*/

#include <stdio.h>
#define	SWN		3	/* 课程数 */
#define NAMELEN		20	/* 姓名最大字符数 */
#define CODELEN		10	/* 学号最大字符数 */
#define FNAMELEN	80	/* 文件名最大字符数 */
#define BUFLEN		80	/* 缓冲区最大字符数 */
/* 课程名称表 */
char schoolwork[SWN][NAMELEN+1] = "Chinese","Mathematic","English";
struct record

	char	name[NAMELEN+1];	/* 姓名 */
	char 	code[CODELEN+1];	/* 学号 */
	int 	marks[SWN];		/* 各课程成绩 */
	int total;			/* 总分 */
stu;

struct node

	char	name[NAMELEN+1];	/* 姓名 */
	char 	code[CODELEN+1];	/* 学号 */
	int 	marks[SWN];		/* 各课程成绩 */
	int 	total;			/* 总分 */
	struct	node *next;		/* 后续表元指针 */
*head;	/* 链表首指针 */

int total[SWN];		/* 各课程总分 */
FILE *stfpt;		/* 文件指针 */
char stuf[FNAMELEN];	/* 文件名 */

/* 从指定文件读入一个记录 */
int readrecord(FILE *fpt,struct record *rpt)

	char buf[BUFLEN];
	int i;
	if(fscanf(fpt,"%s",buf)!=1)
		return 0;	/* 文件结束 */
	strncpy(rpt->name,buf,NAMELEN);
	fscanf(fpt,"%s",buf);
	strncpy(rpt->code,buf,CODELEN);
	for(i=0;i<SWN;i++)
		fscanf(fpt,"%d",&rpt->marks[i]);
	for(rpt->total=0,i=0;i<SWN;i++)
		rpt->total+=rpt->marks[i];
	return 1;

/* 对指定文件写入一个记录 */
writerecord(FILE *fpt,struct record *rpt)

	int i;
	fprintf(fpt,"%s\\n",rpt->name);
	fprintf(fpt,"%s\\n",rpt->code);
	for(i=0;i<SWN;i++)
		fprintf(fpt,"%d\\n",rpt->marks[i]);
	return ;


/* 显示学生记录 */
displaystu(struct record *rpt)

	int i;
	printf("\\nName   : %s\\n",rpt->name);
	printf("Code   : %s\\n",rpt->code);
	printf("Marks  :\\n");
	for(i=0;i<SWN;i++)
		printf("       %-15s : %4d\\n",schoolwork[i],rpt->marks[i]);
	printf("Total  : %4d\\n",rpt->total);


/* 计算各单科总分 */
int totalmark(char *fname)

	FILE *fp;
	struct record s;
	int count,i;
	if((fp=fopen(fname,"r"))==NULL)
	
		printf("Can't open file %s.\\n",fname);
		return 0;
	
	for(i=0;i<SWN;i++)
		total[i]=0;
	count=0;
	while(readrecord(fp,&s)!=0)
	
		for(i=0;i<SWN;i++)
			total[i]+=s.marks[i];
		count++;
	
	fclose(fp);
	return count;	/* 返回记录数 */


/* 列表显示学生信息 */
void liststu(char *fname)

	FILE *fp;
	struct record s;
	if((fp=fopen(fname,"r"))==NULL)
	
		printf("Can't open file %s.\\n",fname);
		return ;
	
	while(readrecord(fp,&s)!=0)
	
		displaystu(&s);
		printf("\\n      Press ENTER to continue...\\n");
		while(getchar()!='\\n');
	
	fclose(fp);
	return;


/* 构造链表 */
struct node *makelist(char *fname)

	FILE *fp;
	struct record s;
	struct node *p,*u,*v,*h;
	int i;
	if((fp=fopen(fname,"r"))==NULL)
	
		printf("Can't open file %s.\\n",fname);
		return NULL;
	
	h=NULL;
	p=(struct node *)malloc(sizeof(struct node));
	while(readrecord(fp,(struct record *)p)!=0)
	
		v=h;
		while(v&&p->total<=v->total)
		
			u=v;
			v=v->next;
		
		if(v==h)
			h=p;
		else
			u->next=p;
		p->next=v;
		p=(struct node *)malloc(sizeof(struct node));
	
	free(p);
	fclose(fp);
	return h;


/* 顺序显示链表各表元 */
void displaylist(struct node *h)

	while(h!=NULL)
	
		displaystu((struct record *)h);
		printf("\\n      Press ENTER to continue...\\n");
		while(getchar()!='\\n');
		h=h->next;
	
	return;

/* 按学生姓名查找学生记录 */
int retrievebyn(char *fname, char *key)

	FILE *fp;
	int c;
	struct record s;
	if((fp=fopen(fname,"r"))==NULL)
	
		printf("Can't open file %s.\\n",fname);
		return 0;
	
	c=0;
	while(readrecord(fp,&s)!=0)
	
		if(strcmp(s.name,key)==0)
		
			displaystu(&s);
			c++;
		
	
	fclose(fp);
	if(c==0)
		printf("The student %s is not in the file %s.\\n",key,fname);
	return 1;


/* 按学生学号查找学生记录 */
int retrievebyc(char *fname, char *key)

	FILE *fp;
	int c;
	struct record s;
	if((fp=fopen(fname,"r"))==NULL)
	
		printf("Can't open file %s.\\n",fname);
		return 0;
	
	c=0;
	while(readrecord(fp,&s)!=0)
	
		if(strcmp(s.code,key)==0)
		
			displaystu(&s);
			c++;
			break;
		
	
	fclose(fp);
	if(c==0)
		printf("The student %s is not in the file %s.\\n",key,fname);
	return 1;


main()

	int i,j,n;
	char c;
	char buf[BUFLEN];
	FILE *fp;
	struct record s;
	clrscr();
	printf("Please input the students marks record file's name: ");
	scanf("%s",stuf);
	if((fp=fopen(stuf,"r"))==NULL)
	
		printf("The file %s doesn't exit, do you want to creat it? (Y/N) ",stuf);
		getchar();
		c=getchar();
		if(c=='Y'||c=='y')
		
			fp=fopen(stuf,"w");
			printf("Please input the record number you want to write to the file: ");
			scanf("%d",&n);
			for(i=0;i<n;i++)
			
				printf("Input the student's name: ");
				scanf("%s",&s.name);
				printf("Input the student's code: ");
				scanf("%s",&s.code);
				for(j=0;j<SWN;j++)
				
					printf("Input the %s mark: ",schoolwork[j]);
					scanf("%d",&s.marks[j]);
				
				writerecord(fp,&s);
			
			fclose(fp);
		
	
	fclose(fp);
	getchar();
	/*clrscr();*/
	puts("Now you can input a command to manage the records.");
	puts("m : mean of the marks.");
	puts("t : total of the marks.");
	puts("n : search record by student's name.");
	puts("c : search record by student's code.");
	puts("l : list all the records.");
	puts("s : sort and list the records by the total.");
	puts("q : quit!");
	while(1)
	
		puts("Please input command:");
		scanf(" %c",&c);		/* 输入选择命令 */
		if(c=='q'||c=='Q')
		
			puts("\\n Thank you for your using.");
			break;		/* q，结束程序运行 */
		
		switch(c)
		
			case 'm': /* 计算平均分 */
			case 'M':
				if((n=totalmark(stuf))==0)
				
					puts("Error!");
					break;
				
				printf("\\n");
				for(i=0;i<SWN;i++)
					printf("%-15s's average is: %.2f.\\n",schoolwork[i],(float)total[i]/n);
				break;
			case 't': /* 计算总分 */
			case 'T':
				if((n=totalmark(stuf))==0)
				
					puts("Error!");
					break;
				
				printf("\\n");
				for(i=0;i<SWN;i++)
					printf("%-15s's total mark is: %d.\\n",schoolwork[i],total[i]);
				break;
			case 'n': /* 按学生的姓名寻找记录 */
			case 'N':
				printf("Please input the student's name you want to search: ");	
				scanf("%s",buf);
				retrievebyn(stuf,buf);
				break;
			case 'c': /* 按学生的学号寻找记录 */
			case 'C':
				printf("Please input the student's code you want to search: ");	
				scanf("%s",buf);
				retrievebyc(stuf,buf);
				break;
			case 'l': /* 列出所有学生记录 */
			case 'L':
				liststu(stuf);
				break;
			case 's': /* 按总分从高到低排列显示 */
			case 'S':
				if((head=makelist(stuf))!=NULL)
					displaylist(head);
				break;
			default: break;