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[Leetcode]单链表回顾

news 2025/7/2 10:00:14

一.链表结构

二 .初始化链表

三.建立链表

3.1头插法建立单链表（输入的顺序为倒序）

void createListInsertionMethod(LinkList& head)
{
node* s;
   int flag = 1;
   char ch;
   while(flag)
   {
       c = getchar();
       if(c != '$')
       {
       s = new node;
       s->ch = c;
           s->next = head->next;
           head->next = s;
       }
       else
       {
       flag = 0;
       }
   }
}

3.2尾插法建立单链表（输入的顺序为顺序）

//尾插法建立单链表
void creatListTailInsertionMethod(LinkList& head)
{
   char ch;
   node* p,*q;
   int flag = 1;
   p = head;
   q = NULL;
   while (flag)
   {
       ch = getchar();
       if (ch != '$')
       {
           q = new node;
           p->next = q;
           q->ch = ch;
           p = q;
           q->next = NULL;
       }
       else
       {
           flag = 0;
       }
   }
}

四.求链表的长度

//求出链表的长度
int sizeofList(LinkList head)
{
   if (head != NULL)
   {
       int size = 1;
       node* p = head->next;
       while (p != NULL)
       {
           size++;
           p = p->next;
       }
       return size - 1;
   }
   return 0;
}

五.输出链表的内容

//输出链表的内容
void outputListContent(LinkList head)
{
   cout << "The output of List is: ";
   node* p = head->next; // 跳过头节点，从第一个实际节点开始
   if (p == NULL)
   {
       cout << "The list is empty." << endl;
       return;
   }

   while (p != NULL)
   {
       cout << p->ch << " ";
       p = p->next;
   }
   cout << endl; // 在输出结束后换行
}

六.查找链表中的第i个内容

//查找单链表中的第i个节点
void searchByIndex(LinkList head, int index)
{
   if (head != NULL)
   {
       int size = sizeofList(head);
       if (index > size)
       {
           cout << "输入的index不合法。" << endl;
           return;
       }
       node* p = new node;
       p = head->next;
       for (int i = 1;i < index;i++)
       {
           p = p->next;
       }
       cout << "The content of " << index << " is :" << p->ch << endl;
   }
   else
   {
cout << "链表为NULL" << endl;
   return;
   }

}

七.按照值查找

//按照值查找
void searchByContent(const LinkList head, char ch,node*& aim)
{
   if (head != NULL)
   {
       node* p = head->next;
       while (p->ch != ch)
       {
           if (p == NULL)
           {
               cout << "找不到ch" << endl;
               return;
           }
           p = p->next;
       }
       aim = p;
   }
   else
   {
       cout << "链表为NULL" << endl;
       return;
   }
}

八.单链表插入操作

//单链表插入操作
void insert(LinkList& head, int index, char ch)
{
   if (head != NULL)
   {
       int len = sizeofList(head);
       if (index > len)
       {
           cout << "插入操作的index输入不合法" << endl;
           return;
       }
       else
       {
           int i = 1;
           node* p = head->next;
           while (i != index - 1)
           {
               p = p->next;
               i++;
           }

           node* s = new node;
           s->next = p->next;
           p->next = s;
           s->ch = ch;
       }
   }
}

九.单链表删除操作

//单链表删除操作
bool delList(LinkList& head,int index)
{
   if (head != NULL)
   {
       int len = sizeofList(head);
       if (len < index)
       {
           cout << "删除操作的Index输入不合法" << endl;
           return false;
       }
       int i = 1;
       node* p = head->next;
       while (i != index - 1)
       {
           p = p->next;
           i++;
       }
       node* q = p->next;
       p->next = q->next;
       return true;
   }
   else
   {
       cout << "删除操作的输入链表为NULL" << endl;
       return false;
   }
}

十.Coding

#include<iostream>

using namespace std;

typedef struct node
{
char ch;
node* next;
}*LinkList,Node;

//初始化单链表
void initList(LinkList& head)
{
head = new node;
head->next = NULL;
}

/*头插法建立单链表
void createListInsertionMethod(LinkList& head)
{
node* s;
   int flag = 1;
   char ch;
   while(flag)
   {
       c = getchar();
       if(c != '$')
       {
       s = new node;
       s->ch = ch;
           s->next = head->next;
           head->next = s;
       }
       else
       {
       flag = 0;
       }
   }
}
*/

   while (p != NULL)
   {
       cout << p->ch << " ";
       p = p->next;
   }
   cout << endl; // 在输出结束后换行
}

           node* s = new node;
           s->next = p->next;
           p->next = s;
           s->ch = ch;
       }
   }
}

int main()
{
   //input:
   //dsaf$
   LinkList head;
   initList(head);
   creatListTailInsertionMethod(head);
   outputListContent(head);
   cout << "The size of List is : " << sizeofList(head) << endl;
   int index = 3;
   cout << "链表第" << index << "个的内容是 : " << endl;
   searchByIndex(head, index);
   node* aim = NULL;
   searchByContent(head, 'a', aim);
   cout << "The aimed content of node is : " << aim->ch << endl;
   insert(head, 3, '%');
   outputListContent(head);
   cout << "The result of delete function is : " << delList(head, 3) << endl;
   outputListContent(head);
   return 0;
}