写了一个程序,需求是:建立由3个学生数据结点构成的单向动态链表,向每个结点输入学生的数据
(每个学生的数据包括学号、姓名、成绩),然后逐个输出各结点中的数据。
正确的程序如下:
#include<stdio.h>
#include<malloc.h>
#define LEN sizeof(struct student)
struct student
{
int num;
char name[20];
float score;
struct student *next;
} ;
void main()
{
struct student *head,*p,*q;
head=p=(struct student*) malloc(LEN);
scanf("%d,%f,%s",&p->num,&p->score,p->name);
p=(struct student*) malloc(LEN);
scanf("%d,%f,%s",&p->num,&p->score,p->name);
q=(struct student*) malloc(LEN);
scanf("%d,%f,%s",&q->num,&q->score,q->name);
head->next=p;
p->next=q;
q->next=NULL;
p=head;
printf("\n结点 1:%d,%5.1f,%s",p->num,p->score,p->name);
p=p->next;
printf("\n结点 2:%d,%5.1f,%s",p->num,p->score,p->name);
q=p->next;
printf("\n结点 3:%d,%5.1f,%s\n",q->num,q->score,q->name);
}
运行结果为:
输入:
10101,98,li
10102,87,wang
10103,76,qi
输出:
结点 1:10101, 98.0,li
结点 2:10102, 87.0,wang
结点 3:10103, 76.0,qi
错误的程序如下:
#include<stdio.h>
#include<malloc.h>
#define LEN sizeof(struct student)
struct student
{
int num;
char name[2];
float score;
struct student *next;
} ;
void main()
{
struct student *head,*p,*q;
head=p=(struct student*) malloc(LEN);
scanf("%d,%s,%f",&p->num,p->name,&p->score);
p=(struct student*) malloc(LEN);
scanf("%d,%s,%f",&p->num,p->name,&p->score);
q=(struct student*) malloc(LEN);
scanf("%d,%s,%f",&q->num,q->name,&p->score);
head->next=p;
p->next=q;
q->next=NULL;
p=head;
printf("\n结点 1:%d,%5.1f,%s",p->num,p->score,p->name);
p=p->next;
printf("\n结点 2:%d,%5.1f,%s",p->num,p->score,p->name);
q=p->next;
printf("\n结点 3:%d,%5.1f,%s\n",q->num,q->score,q->name);
}
运行结果为:
输入:
10101,wang,,98
10102,wani,,87
10103,wangx,,76
输出:
结点 1:10101, 0.0,wang,,98 p?
结点 2:10102, 0.0,wani,,878p?
结点 3:10103, 0.0,wangx,,7
想要得到的结果应该为:
结点 1:10101, 98.0,wang,
结点 2:10102, 87.0,wani,
结点 3:10103, 76.0,wangx,
如果将想要输入的字符串数组放在输入的中间,就极有可能导致
在输入完字符串之后,还会将接下来输入的内容输入到字符串中,
会导致输出值发生混乱,得不到想要的结果,因而,最好将字符串
输入参数放在参数列表的最后,这样就可以避免输出产生错误。