单链表基本操作

  1 #include <iostream>
  2 using namespace std;
  3 
  4 struct Node
  5 {
  6     int val;
  7     Node *next;
  8     Node(int x) :val(x), next(nullptr){}
  9 };
 10 
 11 //创建带有头结点的单链表
 12 void Create(Node *head)
 13 {
 14     int n;
 15     Node *p(head), *q;
 16     cout << "请输入元素个数及相应数据:";
 17     cin >> n;
 18     while (n--)
 19     {
 20         int value;
 21         cin >> value;
 22         q = new Node(value);
 23         q->next = nullptr;
 24         p->next = q;
 25         p = q;
 26     }
 27 }
 28 
 29 //获得链表长度
 30 int GetSize(Node *head)
 31 {
 32     int num = 0;
 33     Node *p = head->next;
 34     while (p)
 35     {
 36         num++;
 37         p = p->next;
 38     }
 39     return num;
 40 }
 41 //输出链表元素
 42 void Print(Node *head)
 43 {
 44     Node *p = head->next;
 45     while (p)
 46     {
 47         cout << p->val << ‘ ‘;
 48         p = p->next;
 49     }
 50 }
 51 
 52 //删除值为x的结点
 53 void Delete(Node *head, int x)
 54 {
 55     Node *p(head), *q;
 56     while (p->next && p->next->val != x)
 57     {
 58         p = p->next;
 59     }
 60     if (p->next)
 61     {
 62         q = p->next;
 63         p->next = q->next;
 64         delete[] q;
 65     }
 66     else
 67     {
 68         cout << "链表不存在值为" << x << "的结点" << endl;
 69     }
 70 }
 71 
 72 //链表逆序
 73 void Reverse(Node *head)
 74 {
 75     Node *p(head->next), *q(head->next);
 76     head->next = nullptr;
 77     while (p)
 78     {
 79         q = q->next;
 80         p->next = head->next;
 81         head->next = p;
 82         p = q;
 83     }    
 84 }
 85 
 86 //在升序链表中插入结点使之仍然有序
 87 void Insert(Node *head, Node *t)
 88 {
 89     Node *p(head);
 90     while (p->next && p->next->val < t->val)
 91     {
 92         p = p->next;
 93     }
 94     t->next = p->next;
 95     p->next = t;
 96 }
 97 //按升序排列
 98 void Sort(Node *head)
 99 {
100     Node *p, *q;
101     p = head->next;
102     head->next = nullptr;
103     while (p)
104     {
105         q = p;
106         p = p->next;
107         q->next = nullptr;
108         Insert(head, q);
109     }
110 }
111 
112 void Tips()
113 {
114     cout << "\n请按键选择相应操作" << endl;
115     cout << "-------------------------" << endl;
116     cout << "1.输出链表" << endl;
117     cout << "2.删除链表某一结点" << endl;
118     cout << "3.链表逆序" << endl;
119     cout << "4.按升序排列" << endl;
120     cout << "-------------------------" << endl;
121 }
122 int main()
123 {
124     Node *head = new Node(0);
125     head->next = nullptr;
126     Create(head);
127     Tips();
128     char c;
129     while (cin >> c)
130     {
131         switch (c)
132         {
133         case ‘1‘:
134             Print(head);
135             break;
136         case‘2‘:
137             int valToDelete;
138             cout << "请输入要删除结点的值:";
139             cin >> valToDelete;
140             Delete(head, valToDelete);
141             Print(head);
142             break;
143         case‘3‘:
144             Reverse(head);
145             Print(head);
146             break;
147         case ‘4‘:
148             Sort(head);
149             Print(head);
150             break;
151         default:
152             break;
153         }
154         Tips();
155     }
156     
157 }