例1-5 学生数据.c

王为青 刘变红 编著《C语言高级编程及实例剖析》源代码

/* Note:Your choice is C IDE */
#include <stdio.h>
#include <stdlib.h>
struct stud
{
   char name[20];
   long num;
   int age;
   char sex;
   float score;
   struct stud * next;
};
void new_record();
void listall();
struct stud *head, *cur, *newp;
void main()
{
    char ch;
	int flag=1;
	head=NULL;
	while(flag)
	{
	   printf("type 'E' or 'e' to enter new record,");
	   printf("\n type 'L' or 'l' to list all records:");
       ch=getchar();
	   getchar();
	   switch(ch)
	   {
	      case 'e':
	      case 'E':new_record();
		        break;
          case 'l':
	      case 'L':listall();
		        break;
	      default:flag=0;
	   };
	}
}
void new_record(void)
{
	char numstr[20];
	newp=(struct stud * )malloc(sizeof(struct stud)); /* 开辟新结点 */
	if(head==NULL)                          /* 原来为空表 */
		head=newp;
	else
	{
		cur=head;                            /* 原来已有结点 */
		while(cur->next!=NULL)
			cur=cur->next;
		cur->next=newp;
	}
	cur=newp;                                 /* 使this指向新结点 */
  printf("enter name:");                   /* 以下输入新结点数据 */
  gets(cur->name);
  printf("enter number:");
  gets(numstr);
  cur->num=atol(numstr);
  printf("enter age:");
  gets(numstr);
  cur->age=atoi(numstr);
  printf("enter sex:");
  cur->sex=getchar();
  getchar();
  printf("enter score:");
  gets(numstr);
  cur->score=atof(numstr);
  cur->next=NULL;                           /* 新结点不再指向其它结点 */
}

void listall(void)
{
	int i=0;
	if(head==NULL)
	{
		printf("\n empty list.\n");
		return;
	}
	cur=head;                  /* 使this指向第一个结点 */
	do
	{
		printf("\n record number %d\n",++i);
		printf("name: %s\n",cur->name);
		printf("num: %ld\n",cur->num);
		printf("age: %d\n",cur->age);
		printf("sex: %c\n",cur->sex);
		printf("score: %6.2f\n",cur->score);
		cur=cur->next;
	}while (cur!=NULL);        /* 打印完最后一个结点不再打印 */
}