c语言学生管理系统

创建结构体里面包含学生的各种信息。

struct xs {
	int xh;
	char xm[20];
	int gs, yy, wl;
	double pj;
	struct xs* next;
};

创建菜单

void menu()
{
	printf("\n************************************\n");
	printf("*         学生管理系统（1.0）        *\n");
	printf("  ************************************\n");
	printf("  ************************************\n");
	printf("*             1.创建链表             *\n");
	printf("*             2.显示链表             *\n");
	printf("*             3.保存文件             *\n");
	printf("*             4.读取文件             *\n");
	printf("*             5.系统退出             *\n");
	printf("  ************************************\n");
	printf("*          请选择操作：(1-5)         *\n");
	printf("  ************************************\n");
}

创建链表

struct xs* create()
{
	struct xs* hd = (struct xs*)malloc(sizeof(struct xs)), * p = NULL, * r = NULL;
	hd->next = NULL;
	r = hd;
	printf("请输入学生人数： ");
	scanf("%d", &rs);
	for (int i = 1; i <= rs; i++)
	{
		printf("请输入第%d个学生成绩信息： \n", i);
		p = (struct xs*)malloc(sizeof(struct xs));
		p->next = NULL;
		printf("学号：");
		scanf("%d", &p->xh);
		printf("姓名：");
		scanf("%s", &p->xm);
		printf("高数：");
		scanf("%d", &p->gs);
		printf("英语：");
		scanf("%d", &p->yy);
		printf("物理：");
		scanf("%d", &p->wl);
		p->pj = (p->gs + p->yy + p->wl) / 3.0;
		r->next = p;
		r = r->next;
	}
	printf("创建链表完毕，请按任意键继续！\n");
	_getch();
	return hd;
}

打印信息

void print(struct xs* hd)
{
	if (hd == NULL)
	{
		printf("当前链表为空，请按任意键继续！");
		_getch();
		return;
	}
	struct xs* p = hd->next;
	printf("   学号  姓名  高数  英语 物理  平均  \n");
	printf("  ************************************\n");
	while (p != NULL)
	{
		printf("    %d%     -6s     %d     %d%     d     %.2f\n", p->xh, p->xm, p->gs, p->yy, p->wl, p->pj);
		p = p->next;
	}
	printf("  ************************************\n");
	printf("链表显示完毕，请按任意键继续！\n");
	_getch();
}

数据保存

void save(struct xs* hd)
{
	if (hd == NULL)
		printf("当前链表为空，请按任意键继续！");
	else
	{
		struct xs* p = NULL;
		FILE* fp = fopen("1.txt", "w");
		fprintf(fp, "%d\n", rs);
		p = hd->next;
		while (p != NULL)
		{
			fprintf(fp, "%d%s%d%d%d%lf\n", p->xh, p->xm, p->yy, p->wl, p->pj);
			p = p->next;
		}
		fclose(fp);
		printf("数据保存结束，请按任意键继续！\n");
	}
	_getch();
}

读取文件

struct xs* read()
{
	struct xs* hd = (struct xs*)malloc(sizeof(struct xs)), * p = NULL, * r = NULL;
	FILE* fp = fopen("1.txt", "r");
	hd->next = NULL;
	r = hd;
	fscanf(fp, "%d\n", &rs);
	for (int i = 1; i <= rs; i++)
	{
		p = (struct xs*)malloc(sizeof(struct xs));

		fscanf(fp, "%d%s%d%d%d%lf\n", &p->xh, p->xm, &p->gs, &p->yy, &p->wl, &p->pj);
		p->next = NULL;
		r->next = p;
		r = r->next;
	}
	printf("读取文件结束，请按任意键继续！\n");
	_getch();
	return hd;
}

释放资源

void sflb(struct xs* hd)
{
	struct xs* p = NULL;
	while (hd != NULL && hd->next != NULL)
	{
		p = hd->next;
		hd->next = p->next;
		free(p);
	}
	free(hd);
}

主函数

void main()
{
	struct xs* head = NULL;
	int xz;
	do
	{
		system("cls");
		menu();
		scanf("%d", &xz);
		switch (xz)
		{
		case 1:sflb(head); head = create(); break;
		case 2:print(head); break;
		case 3:save(head); break;
		case 4:sflb(head); head = read(); break;
		case 5:sflb(head);
		}
	} while (xz != 5);
}