一个链表程序

把数据分组存储到内存中

 

组1-----》组2------组3

 |              |           |

g11         g21      g31

 |              |           |

g12         g22      g32

 |              |           |

 

一个简单的方式就是如上图所示，各组数据保存在一个链表中，再用一个链表把组关联起来

 

定义一个数据结点基类，达到一个链表结构实现多种数据结点

 

#include <iostream.h> #include <stdio.h> #include <string.h> #define ARRSIZE 64 class Object { public: Object() { } virtual int IsEqual(Object &) = 0; virtual void Show() = 0; virtual ~Object() { } }; class DataNode:public Object { public: char strNum[32]; int IsEqual(Object &obj) { DataNode &temp = (DataNode &)obj; if (strcmp(strNum, temp.strNum) == 0) { return 1; } else { return 0; } } DataNode() {} DataNode(char* s) { strcpy(strNum, s); } void Show() { cout << strNum << " "; } protected: private: }; class Node { public: Node() { Info = NULL; next = NULL; } void FillInfo(Object* obj) { Info = obj; } Object* Info; Node* next; friend class List; protected: private: }; class List { public: List() { head = NULL; tail = NULL; } ~List() { DeleteList(); } void AddNode(Node*); void DeleteNode(Object&); Node* LookUp(Object &); void ShowList(); void DeleteList(); Node* head; Node* tail; protected: private: }; class ArrNode:public Object { public: char arrName[32]; List* list; ArrNode() { list = NULL; } ArrNode(char* s) { list = NULL;// strcpy(arrName, s); } ~ArrNode() { if (list != NULL) { delete list; } } protected: int IsEqual(Object &obj) { ArrNode &temp = (ArrNode &)obj; if (strcmp(arrName, temp.arrName) == 0) { return 1; } else { return 0; } } void Show() { cout << arrName << " "; } }; void List::AddNode(Node* node) { if (head == NULL) { head = node; tail = node; tail->next = NULL; } else { tail->next = node; tail = node; tail->next = NULL; } } void List::DeleteNode(Object& obj) { Node* p = head; Node* q = NULL; if (p == NULL) { return; } if (head->Info->IsEqual(obj)) { if (head == tail) { head = NULL; tail = NULL; } else { head = head->next; } delete p->Info; delete p; } else { while (p->next != NULL) { q = p->next; if (q->Info->IsEqual(obj)) { p->next = q->next; delete q->Info; delete q; break; } p = p->next; } } } Node* List::LookUp(Object &obj) { Node* p = head; while (p != NULL) { if (p->Info->IsEqual(obj)) { return p; } p = p->next; } return NULL; } void List::ShowList() { Node* p = head; while (p != NULL) { p->Info->Show(); p = p->next; } cout << endl; } void List::DeleteList() { Node* q = NULL; Node* p = head; while (p != NULL) { delete p->Info; q = p; p = p->next; delete q; } } int getStr(char* str, char s[][ARRSIZE]) { int num = 0; int len = 0; char* p = str; while (*p != '/0') { if (*p != ' ' && *p != '/n') { s[num][len++] = *p; if (*(p + 1) == ' ') { s[num][len] = '/0'; num++; len = 0; if (num == 3) { return num; } } } p++; } s[num][len] = '/0'; if (len == 0) { num--;//deal with "in " } return num; } void showHelp() { cout << "======================" << endl; cout << "in 123 groupName insert a value into the group" << endl; cout << "show groupName type all the values in the group" << endl; cout << "del 123 groupName del the value 123 in the group" << endl; cout << "======================" << endl; } int main() { List arrlist; //create the default group ArrNode* p = new ArrNode; strcpy(p->arrName, "default"); p->list = new List; Node* pn = new Node; pn->FillInfo(p); arrlist.AddNode(pn); char str[ARRSIZE]; char s[3][ARRSIZE]; int num = 0; showHelp(); while (1) { memset(s, 0, 3*ARRSIZE); cout << "put in the command:" << endl; fgets(str, ARRSIZE, stdin); fflush(stdin);///////////// num = getStr(str, s); if (num >= 3) { cout << "too many param" << endl; continue; } Node * pos; if (strcmp(s[0], "in") == 0) {//insert into the default group if (num == 1) { strcpy(s[2], "default"); } else if (num == 0) { cout << "in number group" << endl; continue; } if (pos = arrlist.LookUp(ArrNode(s[2]))) { if (((ArrNode*)pos->Info)->list->LookUp(DataNode(s[1]))) { cout << "find " << s[1] << " " << s[2] << endl; } else { Node* dn = new Node; dn->FillInfo(new DataNode(s[1])); ((ArrNode*)pos->Info)->list->AddNode(dn); cout << "insert " << s[1] << " " << s[2] << endl; } } else {//create a new group ArrNode* tmpNode = new ArrNode(s[2]); tmpNode->list = new List; pos = new Node; pos->FillInfo(tmpNode); arrlist.AddNode(pos); DataNode* dNode = new DataNode(s[1]); Node* dn = new Node; dn->FillInfo(dNode); ((ArrNode*)pos->Info)->list->AddNode(dn); cout << "insert " << s[1] << " " << s[2] << endl; } } else if (strcmp(s[0], "show") == 0) {//default if (num == 0) { strcpy(s[1], "default"); } else if (num > 1) { cout << "show group" << endl; continue; } pn = arrlist.LookUp(ArrNode(s[1])); if (pn != NULL) { ((ArrNode*)pn->Info)->list->ShowList(); } else { cout << "no this group" << endl; } } else if (strcmp(s[0], "del") == 0) { if (num == 1) { strcpy(s[2], "default"); } else if (num != 2) { cout << "please put in: del value group" << endl; continue; } pn = arrlist.LookUp(ArrNode(s[2])); if (pn != NULL) { ((ArrNode*)pn->Info)->list->DeleteNode(DataNode(s[1])); } else { cout << "no group named: " << s[2] << endl; } } else if (strcmp(s[0], "bye") == 0) { break; } else if (strcmp(s[0], "help") == 0) { showHelp(); } else if (strcmp(s[0], "group") == 0) { arrlist.ShowList(); } } return 0; }

 

使用空指针也可以来实现结点和数据分离

#include <stdio.h> #include <string.h> #include <iostream.h> struct Node { Node* next; void* Info; }; struct List { Node* head; Node* tail; }; struct DataNode { char str[32]; }; struct ArrNode { char arrName[32]; List* list; }; int main() { Node t; ArrNode * ap = new ArrNode; strcpy(ap->arrName, "how you doing"); t.Info = ap; cout << ((ArrNode*)t.Info)->arrName << endl; return 0; }