单链表基本操作

#include <iostream>
using namespace std;

struct Node
{
int val;
Node *next;
Node(int x) :val(x), next(nullptr){}
};

//创建带有头结点的单链表
void Create(Node *head)
{
int n;
Node *p(head), *q;
cout << "请输入元素个数及相应数据:";
cin >> n;
while (n--)
{
int value;
cin >> value;
q = new Node(value);
q->next = nullptr;
p->next = q;
p = q;
}
}

//获得链表长度
int GetSize(Node *head)
{
int num = 0;
Node *p = head->next;
while (p)
{
num++;
p = p->next;
}
return num;
}
//输出链表元素
void Print(Node *head)
{
Node *p = head->next;
while (p)
{
cout << p->val << ' ';
p = p->next;
}
}

//删除值为x的结点
void Delete(Node *head, int x)
{
Node *p(head), *q;
while (p->next && p->next->val != x)
{
p = p->next;
}
if (p->next)
{
q = p->next;
p->next = q->next;
delete[] q;
}
else
{
cout << "链表不存在值为" << x << "的结点" << endl;
}
}

//链表逆序
void Reverse(Node *head)
{
Node *p(head->next), *q(head->next);
head->next = nullptr;
while (p)
{
q = q->next;
p->next = head->next;
head->next = p;
p = q;
}
}

//在升序链表中插入结点使之仍然有序
void Insert(Node *head, Node *t)
{
Node *p(head);
while (p->next && p->next->val < t->val)
{
p = p->next;
}
t->next = p->next;
p->next = t;
}
//按升序排列
void Sort(Node *head)
{
Node *p, *q;
p = head->next;
head->next = nullptr;
while (p)
{
q = p;
p = p->next;
q->next = nullptr;
Insert(head, q);
}
}

void Tips()
{
cout << "\n请按键选择相应操作" << endl;
cout << "-------------------------" << endl;
cout << "1.输出链表" << endl;
cout << "2.删除链表某一结点" << endl;
cout << "3.链表逆序" << endl;
cout << "4.按升序排列" << endl;
cout << "-------------------------" << endl;
}
int main()
{
Node *head = new Node(0);
head->next = nullptr;
Create(head);
Tips();
char c;
while (cin >> c)
{
switch (c)
{
case '1':
Print(head);
break;
case'2':
int valToDelete;
cout << "请输入要删除结点的值:";
cin >> valToDelete;
Delete(head, valToDelete);
Print(head);
break;
case'3':
Reverse(head);
Print(head);
break;
case '4':
Sort(head);
Print(head);
break;
default:
break;
}
Tips();
}

}