学步园

编辑程序实现单链表的插入

#include <tchar.h>
#include <iostream>
using namespace std;

typedef struct student{
	int data;
	struct student * next; 
} node;

node* create()
{
	node *head, *p, *s;
	int x, cycle = 1;
	head = (node *)malloc(sizeof(node));
	p = head;
	while(cycle)
	{
		cout << "please input the data: ";
		cin >> x;
		cout << endl;
		if( x != 0)
		{
			s = (node *)malloc(sizeof(node));
			s->data = x;
			p->next = s;
			p = s;
		}
		else
		{
			cycle = 0;
		}
		
	}
	p->next = NULL;
	head = head->next;
	return head;
}

int length(node *head)
{
	int n = 0;
	node *p;
	p = head;
	while (p != NULL)
	{
		p = p->next;
		n++;
	}
	return n;
}

void print(node *head)
{
	int n;
	node *p;
	p = head;
	n = length(head);
	cout << "There is " << n << " data in list\n" << endl;
	while(p != NULL)
	{
		cout << p->data << " -> ";
		p = p->next;
	}
	cout << endl;
}



node *insert(node *head, int num)
{
	node *p0, *p1, *p2;
	p1 = head;
	p0 = (node *)malloc(sizeof(node));
	p0->data = num;
	while(p0->data > p1->data && p1->next != NULL)
	{
		p2 = p1;
		p1 = p1->next;
	}
	if(p0->data <= p1->data)
	{
		if(head == p1)//头插入
		{
			p0->next = p1;
			head = p0;
		}
		else//中间插入
		{
			p2->next = p0;
			p0->next = p1;
		}
	}
	else//尾插入
	{
	 	p1->next = p0;
		p0->next = NULL;
	}
	return head;
}

int _tmain(int argc, _TCHAR * argv[])
{
	node *head;
	head = create();
	print(head);
	head = insert(head, 4);
	print(head);
	return 0;
}

双链表插入

#include <tchar.h>
#include <iostream>
using namespace std;

typedef struct student{
	int data;
	struct student * next;
	struct student * pre;
} node;

node* create()
{
	node *head, *p, *s;
	int x, cycle = 1;
	head = (node *)malloc(sizeof(node));
	p = head;
	while(cycle)
	{
		cout << "please input the data: ";
		cin >> x;
		cout << endl;
		if( x != 0)
		{
			s = (node *)malloc(sizeof(node));
			s->data = x;
			p->next = s;
			s->pre = p;
			p = s;
		}
		else
		{
			cycle = 0;
		}
		
	}
	p->next = NULL;
	head = head->next;
	head->pre = NULL;
	return head;
}

int length(node *head)
{
	int n = 0;
	node *p;
	p = head;
	while (p != NULL)
	{
		p = p->next;
		n++;
	}
	return n;
}

void print(node *head)
{
	int n;
	node *p;
	p = head;
	n = length(head);
	cout << "There is " << n << " data in list\n" << endl;
	while(p->next != NULL)
	{
		cout << p->data << " -> ";
		p = p->next;
	}
	cout << p->data << endl;
	while(p->pre !=NULL)
	{
		cout << p->data << " -> ";
		p = p->pre;
	}
	cout << p->data << endl;
}

node *insert(node *head, int num)  
{  
    node *p0, *p1, *p2;  
    p1 = head;  
    p0 = (node *)malloc(sizeof(node));  
    p0->data = num;  
    while(p0->data > p1->data && p1->next != NULL)  
    {  
        p2 = p1;  
        p1 = p1->next; 
    }  
    if(p0->data <= p1->data)  
    {  
        if(head == p1)  //头插入
        {  
            p0->next = p1;  
			p1->pre = p0;
            head = p0;  
        }  
        else  //中间插入
        {  
			p1->pre->next = p0;
			p0->pre = p1->pre;
			p1->pre = p0;
			p0->next = p1;
        }  
    }  
    else  //尾插入
    {  
        p1->next = p0;  
        p0->next = NULL;  
		p0->pre = p1;
    }  
    return head;  
}  

int _tmain(int argc, _TCHAR * argv[])
{
	node *head;
	head = create();
	print(head);
	head = insert(head, 3);
	print(head);
	return 0;
}