单链表常见的面试题，及应用

//编程实现一个单链表的建立/长度/打印
#include<iostream>
#include<cstring>
#include<cstdio>
#include<conio.h>
#include<stdlib.h>
using namespace std;
typedef struct  student
{
int data;
struct student *next;
}node;
node *creat()//单链表的建立
{
node *head,*p,*s;
int x,cycle=1;
head=new node;
p=head;
while(cycle)
{
printf("input the data\n");
scanf("%d",&x);
if(x!=0)
{
s=new node;
s->data=x;
p->next=s;
p=s;
}
else
cycle=0;

}
head=head->next;
p->next=NULL;
return head;
}
node *del(node *head,int num)//实现单链表删除节点。
{
node *p,*q;
p=head;
while(p->next!=NULL)
{
if(p->data==num)
{
if(p==head)
{
head=p->next;
free(p);
return head;
}
else
{
//printf("p=%d,q=%d\n",p->data,q->data);
q->next=p->next;
}
}
q=p;
p=p->next;

}
return head;
}
node *insert(node *head,int num)
{
node *p0,*p1,*p2;
p1=head;
p0=new node;
p0->data=num;
while(p0->data>p1->data&&p1->next!=NULL)
{
p2=p1;p1=p1->next;
}
// printf("p0=%d,p1=%d,p2=%d\n",p0->data,p1->data,p2->data);
if(p0->data<=p1->data)
{
if(head==p1)
{
p0->next=p1;
head=p0;
}
else
{
p2->next=p0;
p0->next=p1;
}

}
else
{
p1->next=p0;
p0->next=NULL;
}
return (head);
}
void print(node *head)//单链表打印
{
node *p=head;
p=head;
while(p!=NULL)
{
printf("%d ",p->data);
p=p->next;
}
printf("\n");
}
int length(node *head)
{
int n=0;
node *p;
p=head;
while(p!=NULL)
{
p=p->next;
n++;
}
return n;
}
node *sort(node *head)
{
node *p;

int n=length(head);
int i,j,temp;
if(head==NULL||head->next==NULL)
return head;
p=head;
for(i=0;i<n;i++)
{
p=head;//???????
for(j=i+1;j<n;j++)
{
if(p->data>p->next->data)
{
temp=p->data;
p->data=p->next->data;
p->next->data=temp;
}
p=p->next;
}
}
return head;
}
node *reverse(node *head)//单链表的逆置
{
node *p1,*p2,*p3;
if(head==NULL||head->next==NULL)
return head;
p1=head;
p2=p1->next;
while(p2)
{
p3=p2->next;
p2->next=p1;
p1=p2;
p2=p3;
}
head->next=NULL;
head=p1;
return head;
}
int  main()
{
node *head;
head=creat();
printf("创建链表为\n");
print(head);
int t1,t2;
printf("请输入删除的数\n");
scanf("%d",&t1);
head=del(head,t1);
print(head);
printf("请输入插入的数\n");
scanf("%d",&t2);
head= insert(head,t2);
print(head);
printf("单链表排序从小到大\n");
head=sort(head);
print(head);
printf("链表逆置\n");
head=reverse(head);
print(head);
return 0;
}