该代码主要是针对对链表操作不是很熟悉的朋友，也是自己在面试当中经常 碰到的编程问题,因此利用业余时间写下了此练习性质的程序。以下是源代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct st{
char name[10];
int score;
struct st *next;
};
void print(struct st*);
/*链表头节点的初始化*/
struct st *init()
{
struct st *head;
head =malloc(sizeof(struct st));
head->score =-1;
memset(head->name,0x00,sizeof(head->name));
head->next=NULL;
if (head ==NULL)
return NULL;
else
return head;
}
/*插入节点，尾节点的插入*/
int pushlist(struct st *ptr,char *name,int score)
{
struct st *e,*ep;
ep =e =ptr;
if (e->score==-1)
{
memcpy(e->name,name,strlen(name));
e->score =score;
return 0;
}
while (e!=NULL)
{
ep =e;
e =e->next;
}
e =malloc(sizeof(struct st));
if (e==NULL)
{
return -1;
}
memcpy(e->name,name,strlen(name));
e->score =score;
ep->next =e;
e->next=NULL;
return 0;
}
/*转置函数*/
void reverse(struct st **ptr)
{
struct st *p=*ptr;
struct st *q=NULL;
struct st *r;
while (p)
{
r =p->next;
p ->next=q;
q =p;
p =r;
}
*ptr =q;
}
/*找到节点的最小值*/
struct st * findmin(struct st *ptr)
{
struct st *cur=ptr;
struct st *tmp;
struct st *min =cur;
for (cur=ptr;cur!=NULL;cur =cur->next)
{
if (cur->score < min->score)
{
min =cur;
}
}
return min;
}
/*释放单个节点*/
struct st *freeNode(struct st *tmp,struct st *head)
{
struct st *cur,*p=head;
if (tmp ==head)
{
p =(head)->next;
free(head);
head =NULL;
head =p;
return head;
}
for (cur =(head)->next;cur!=NULL;cur =cur->next)
{
if (cur ==tmp)
{
p->next=cur->next;
free(cur);
cur =NULL;
return head;
}
p =p->next;
}
if (cur==NULL)
{
printf("NULL is");
return NULL;
}
}
/*将最小值插入到新创建头内*/
struct st *sort(struct st *ptr)
{
struct st *cur=ptr;
struct st *tmp;
struct st *head=ptr;
struct st *e,*ep;
int i=0;
struct st *newhead=init();
e=ep =newhead;
while (1)
{
tmp =findmin(head);
if (e ->score ==-1)
{
memcpy(e->name ,tmp->name,strlen(tmp->name));
e->name[strlen(tmp->name)]='\0';
e->score=tmp->score;
head =freeNode(tmp,head);
if (head ==NULL)
break;
continue;
}
while (e)
{
ep =e;
e =e->next;
}
e =malloc(sizeof(struct st));
memcpy(e->name ,tmp->name,strlen(tmp->name));
e->name[strlen(tmp->name)]='\0';
e->score=tmp->score;
ep->next =e;
e->next =NULL;
head =freeNode(tmp,head);
if (head ==NULL)
break;
}
return newhead;
}
/*遍历整个链表*/
void print(struct st *ptr)
{
struct st *cur;
for (cur=ptr;cur!=NULL;cur=cur->next)
{
printf("name:%s,score:%d\n",cur->name,cur->score);
}
}
/*释放整个链表*/
void myfree(struct st *ptr)
{
struct st *after;
struct st *cur=ptr;
for (cur=ptr;cur!=NULL;cur=after)
{
after =cur->next;
free(cur);
cur=NULL;
}
}
/*简单的测试*/
int main()
{
struct st *head;
struct st *me;
struct st *sorthead;
head =init();
char name[10];
int value;
int i;
for (i=0;i<10;i++){
value =rand()%100;
sprintf(name,"同学%d",value);
name[strlen(name)]='\0';
pushlist(head,name,value);
}
printf("------ before reverse--------\n");
print(head);
printf("------ reverse after--------\n");
reverse(&head);
print(head);
printf("-------sort -------------\n");
sorthead=sort(head);
print(sorthead);
myfree(sorthead);
}