10.2-7 单链表的就地逆置

  1 #include <iostream>
  2 #include <crtdbg.h>
  3 #include <cstring>
  4 using namespace std;
  5 
  6 typedef int DataType;
  7 //建立链表
  8 class list
  9 {
 10 private:
 11     struct Node
 12     {
 13         DataType data;
 14         Node* next;
 15     };
 16     Node *head;//哨兵位
 17 public:
 18     list()
 19     {
 20         Init();
 21     }
 22     ~list()
 23     {
 24         Delete();
 25     }
 26     void Init();
 27     void Delete();
 28     void Insert(const DataType data);
 29     void Print();
 30     bool Empty()    { return head->next == NULL;}
 31     void ReversedSort(); //就地逆序
 32 };
 33 void list::Init()
 34 {
 35     head = new Node;
 36     head->next = NULL;
 37 }
 38 void list::Delete()
 39 {
 40     for(Node *p=head; p != NULL;)
 41     {
 42         Node *pTemp = p->next;
 43         delete p;
 44         p = pTemp;
 45     }
 46     head = NULL;
 47 }
 48 //头插法
 49 void list::Insert(const DataType data)
 50 {
 51     Node *pNew = new Node;
 52     pNew->data = data;
 53     pNew->next = head->next;
 54     head->next = pNew;
 55 }
 56 void list::Print()
 57 {
 58     for (Node *p = head->next; p != NULL; p = p->next)
 59     {
 60         cout << p->data << endl;
 61     }
 62 }
 63 //就地逆序
 64 void list::ReversedSort()
 65 {
 66     Node *pOne = head->next;
 67     Node *pTwo = pOne->next;
 68     Node *pFirst = NULL;
 69     
 70     while(pOne != NULL)
 71     {
 72         // 第二项变第一项，第一项连接第三项
 73         pFirst = head->next;
 74         head ->next = pTwo;
 75         pOne->next = pTwo->next;
 76         pTwo->next = pFirst;
 77 
 78         if (pOne->next != NULL)
 79         {
 80             pTwo = pOne->next;
 81         }
 82         else
 83         {
 84             break;
 85         }
 86     }
 87 }
 88 
 89 int main() 
 90 { 
 91     //检测是否有内存泄露 需要加头文件#include <crtdbg.h>
 92     _CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
 93 
 94     list l;
 95     
 96     for (int i=10; i>0; --i)
 97     {
 98         l.Insert(i);
 99     }
100 
101     l.Print();
102 
103     l.ReversedSort();
104 
105     l.Print();
106 
107     system("pause");
108     return 0; 
109 }