Linked list
Linked list is a kind of data structure and an extremely powerful array. Linked lists can easily add, delete, and insert nodes.
table of Contents
Singly linked list
Beginners generally start with a singly linked list. The operations of a singly linked list generally include: create, modify, insert, output, sort, reverse order, empty, and find length.
1. Create a linked list
Use the structure to define the node, and use the pointer to realize the linked list
1.1 Create Node
Use structure to create linked list nodes
struct NodeList
{
int val;
NodeList *next;
};When you define the nodes of the linked list below, you can directly use NodeList *node to define
1.2 Initialization
Create a singly linked list of n nodes
NodeList *CreateList(int &n)
{
NodeList *head,*node,*end; //创建头节点，中间节点，尾节点
head=new NodeList; //给头结点分配地址
end=head; //令尾节点等于头结点
for(int i=0;i<n;i++)
{
node =new NodeList; //给每一个Node分配地址
cin>>node.val; //输入每一个节点的值
end.next=node; //让尾节点(第一次是头节点)的指针指向下一个节点
end=node; //让尾节点等于新添加的节点
}
end.next=NULL; //给最后一个节点的下一个节点置空
return head; //返回头部指针
}
2. Link list length
Returns the length of the linked list, namely length or size
int length(ListNode *head) //返回链表的长度
{
ListNode *p = new ListNode;
p = head;
int len = 0;
while (p->next != nullptr)
{
p = p->next;
len++;
}
return len;
}
3. Linked list printing
Print the nodes of the linked list through loops
void PrintList(ListNode *head) //打印链表
{
ListNode *p = head;
while (p->next != nullptr)
{
p = p->next;
cout << p->val << " ";
}
}
4. Find nodes
Find whether it exists by traversing (return the position of the first occurrence of the node)
int FindNode(ListNode *head, const int &n) //查找链表中是否存在n，存在返回第一次位置，不存在返回-1
{
ListNode *p = new ListNode;
p = head;
int Pos = 0;
while (p->next != nullptr)
{
p = p->next;
Pos++;
if (p->val == n)
return Pos;
}
return -1;
}
5. Delete node
Find the nth node of the linked list, by modifying the pointer, make the previous node of n nodes point to the next node of n, and release the nth node
bool DeleteNode(ListNode *head, const int n) //删除链表的第n个节点
{
if (length(head) < n)
return false;
ListNode *temp = new ListNode;
for (int i = 0; i < n - 1; i++)
{
head = head->next;
}
temp = head->next;
head->next = head->next->next;
delete (temp);
return true;
}
6. Add nodes
Add nodes in the middle by modifying the pointer
bool AddNode(ListNode *head, const int Pos, const int value) //添加一个节点，在pos这个位置添加一个数值为value的节点
{
if (length(head) < Pos)
return false;
for (int i = 0; i < Pos - 1; i++)
{
head = head->next;
}
ListNode *temp = new ListNode;
temp->val = value;
temp->next = head->next;
head->next = temp;
return true;
}
7. Modify the node
Find the node first, modify the value of the node
bool ChangeNode(ListNode *head, const int Pos, const int Value) //修改节点 修改位置pos上的值为value
{
if (length(head) < Pos)
return false;
for (int i = 0; i < Pos; i++)
{
head = head->next;
}
head->val = Value;
return true;
}Complete code
/**
* @分函数编写单链表
*
*
* @1.链表创建 √
* @2.链表长度 √
* @3.链表打印 √
* @4.查找节点 √ 返回位置
* @5.删除节点 √
* @6.增加节点 √
* @7.修改节点 √
*
*
* @Progra：Zbooo
**/
#include <iostream>
using namespace std;
struct ListNode
{
int val;
ListNode *next;
};
ListNode *CreatNode(int &n) //创建n个节点的链表
{
ListNode *head, *node, *end;
head = new ListNode;
end = head;
for (int i = 0; i < n; i++)
{
node = new ListNode;
cin >> node->val;
end->next = node;
end = node;
}
end->next = nullptr;
return head;
}
void PrintList(ListNode *head) //打印链表
{
ListNode *p = head;
while (p->next != nullptr)
{
p = p->next;
cout << p->val << " ";
}
}
int length(ListNode *head) //返回链表的长度
{
ListNode *p = new ListNode;
p = head;
int len = 0;
while (p->next != nullptr)
{
p = p->next;
len++;
}
return len;
}
int FindNode(ListNode *head, const int &n) //查找链表中是否存在n，存在返回位置，不存在返回-1
{
ListNode *p = new ListNode;
p = head;
int Pos = 0;
while (p->next != nullptr)
{
p = p->next;
Pos++;
if (p->val == n)
return Pos;
}
return -1;
}
bool DeleteNode(ListNode *head, const int &n) //删除链表的第n个节点
{
if (length(head) < n)
return false;
ListNode *temp = new ListNode;
for (int i = 0; i < n - 1; i++)
{
head = head->next;
}
temp = head->next;
head->next = head->next->next;
delete (temp);
return true;
}
bool AddNode(ListNode *head, const int Pos, const int &value) //添加一个节点，在pos这个位置添加一个数值为value的节点
{
if (length(head) < Pos)
return false;
for (int i = 0; i < Pos - 1; i++)
{
head = head->next;
}
ListNode *temp = new ListNode;
temp->val = value;
temp->next = head->next;
head->next = temp;
return true;
}
bool ChangeNode(ListNode *head, const int Pos, const int &Value) //修改节点 修改位置pos上的值为value
{
if (length(head) < Pos)
return false;
for (int i = 0; i < Pos; i++)
{
head = head->next;
}
head->val = Value;
return true;
}
int main()
{
int n;
cin >> n;
ListNode *head = new ListNode;
head = CreatNode(n);
DeleteNode(head, 3);
AddNode(head, 3, 10);
ChangeNode(head, 3, 10);
cout << FindNode(head, 3) << endl;
PrintList(head);
system("pause");
return 0;
}