学校数据结构的课程实验之一。
用到的数据结构：B-树
基本功能：对虚拟书库的图书进行查看、增加、删除、修改。
主函数：
1 #include <iostream> 2 #include "Library.h" 3 using namespace std; 4 int main() 5 { 6 Library myLib=Library("books.txt"); 7 char choice='y'; 8 while(choice=='y') 9 { 10 cout << "请选择操作"<<endl; 11 cout << "--------------------------------" << endl; 12 cout << "1----新书入库" << endl; 13 cout << "2----查看库存" << endl; 14 cout << "3----借阅" << endl; 15 cout << "4----归还" << endl; 16 cout << "5----删除旧书" << endl; 17 cout << "6----修改图书信息" << endl; 18 cout << "--------------------------------" << endl; 19 int option; 20 cin >> option; 21 switch (option) 22 { 23 case 1: myLib.add(); break; 24 case 2: myLib.display(); break; 25 case 3: myLib.lend(); break; 26 case 4: myLib.back(); break; 27 case 5: myLib.remove(); break; 28 case 6: myLib.change(); break; 29 } 30 cout << "继续吗?[y/n]"; 31 cin >> choice; 32 } 33 cout << "是否保存修改？[y/n]"; 34 cin >> choice; 35 if (choice == 'y') 36 myLib.save("books.txt");//需要保存时保存文件 37 return 0; 38 }
图书馆类：
1 #include <fstream> 2 #include <string> 3 #include "B_tree.h" 4 using namespace std; 5 6 struct Book 7 { 8 int number; 9 string name; 10 string introduction; 11 unsigned left; 12 Book(){} 13 Book(int num) :number(num), name(""), introduction(""), left(0){}//只有编号的初始化 14 Book(int num, string nam,string intro, unsigned lef)//完整初始化 15 :number(num),name(nam),introduction(intro),left(lef){} 16 void print()//显示信息 17 { 18 cout << "-------------------------------" << endl; 19 cout << "这本书的信息如下：" << endl; 20 cout << "编号: " << number << endl; 21 cout << "书名: " << name << endl; 22 cout << "简介: " << introduction << endl; 23 cout << "剩余数量: " << left << endl; 24 cout << "-------------------------------" << endl; 25 } 26 bool operator==(const Book &b) const//重载关系运算符 27 { 28 if(this->number == b.number) return true;//编号等即命中 29 else return false; 30 } 31 bool operator<(const Book &b) const 32 { 33 if (this->number < b.number) return true; 34 else return false; 35 } 36 bool operator>(const Book &b) const 37 { 38 if (this->number > b.number) return true; 39 else return false; 40 } 41 }; 42 ofstream outFile;//输出流 43 44 class Library 45 { 46 private: 47 B_tree<Book,3> books; 48 unsigned total; 49 static void readBook(Book &aBook)//写一本书的内容（一定要是静态的） 50 { 51 outFile<<aBook.number<<endl; 52 outFile<<aBook.name<<endl; 53 outFile<<aBook.introduction<<endl; 54 outFile << aBook.left << endl; 55 } 56 void readFile(const char filename[20])//读文件 57 { 58 total = 0; 59 ifstream inFile; 60 inFile.open(filename); 61 char trying; 62 while(inFile.is_open() && !inFile.eof()) 63 { 64 //先试探是否为结束符 65 inFile >> trying; 66 if (trying == '#') break; 67 else 68 { 69 inFile.putback(trying); 70 int number; 71 inFile>>number; 72 string name; 73 inFile>>name; 74 string introduction; 75 inFile>>introduction; 76 unsigned left; 77 inFile>>left; 78 Book aBook=Book(number,name,introduction,left); 79 aBook.print();//显示这本书的信息 80 books.insert(aBook); 81 total+=left; 82 } 83 } 84 cout << "库存共有图书" << total << "本"<<endl; 85 inFile.close(); 86 } 87 void writeFile(const char filename[20])//写文件 88 { 89 outFile.open(filename); 90 books.traverse(readBook); 91 outFile << '#';//此处必须有一个结束标识符 92 outFile.close(); 93 } 94 Book search(int num)//以编号为依据进行查找 95 { 96 Book se_book(num); 97 books.search_tree(se_book); 98 return se_book; 99 } 100 static void print(Book &aBook)//显示信息（必须是静态的） 101 { 102 cout << "-------------------------------" << endl; 103 cout << "这本书的信息如下：" << endl; 104 cout << "编号: " << aBook.number << endl; 105 cout << "书名: " << aBook.name << endl; 106 cout << "简介: " << aBook.introduction << endl; 107 cout << "剩余数量: " << aBook.left << endl; 108 cout << "-------------------------------" << endl; 109 } 110 public: 111 Library(const char filename[20]) 112 { 113 cout << "这是现在的库存信息：" << endl; 114 readFile(filename); 115 } 116 void add()//增加图书 117 { 118 cout << "请输入图书信息(编号 书名 简介 数量)" << endl; 119 int num; 120 string name; 121 string introduction; 122 unsigned left; 123 cin >> num >> name >> introduction >> left; 124 Book new_book = Book(num, name, introduction, left); 125 books.insert(new_book); 126 cout << "这本书已入库，信息如下：" << endl; 127 new_book.print(); 128 total += left; 129 } 130 void display()//查看库存 131 { 132 cout << "这是现在的库存信息：" << endl; 133 books.traverse(print); 134 cout << "库存共有图书" << total << "本" << endl; 135 } 136 void remove()//删除 137 { 138 cout << "请输入要删除的图书编号："; 139 int num; 140 cin >> num; 141 Book &old_book =search(num);//通过编号找到这本书的记录 142 cout << "您即将删除这本书的所有信息：" << endl; 143 old_book.print(); 144 cout << "确定要删除吗？[y/n]"; 145 char choice; 146 cin >> choice; 147 if (choice == 'y') 148 { 149 books.remove(old_book);//删除这本书的记录 150 cout << "编号为" << num << "的书已成功从库中删除" << endl; 151 total--; 152 } 153 } 154 void lend()//借出 155 { 156 cout << "请输入要借出的图书编号："; 157 int num; 158 cin >> num; 159 Book &old_book = search(num);//通过编号找到这本书的记录 160 old_book.left--; 161 cout << "编号为" << num << "的图书已借出1本，下面是这本书的现存信息：" << endl; 162 old_book.print(); 163 total--; 164 } 165 void change()//修改（先删除再添加） 166 { 167 cout << "请输入要修改的图书编号："; 168 int num; 169 cin >> num; 170 Book &old_book = search(num); 171 cout << "这是这本书的当前信息：" << endl; 172 old_book.print();//显示这本书之前的信息 173 books.remove(old_book); 174 cout << "请输入修改后的图书信息（编号 书名 简介 数量）" << endl; 175 string name; 176 string introduction; 177 unsigned left; 178 cin >> num >> name >> introduction >> left; 179 Book new_book = Book(num, name, introduction, left); 180 books.insert(new_book); 181 cout << "这本书的信息已修改为：" << endl; 182 new_book.print(); 183 } 184 void back()//归还 185 { 186 cout << "请输入要归还的图书编号："; 187 int num; 188 cin >> num; 189 Book &old_book = search(num);//通过编号找到这本书的记录 190 old_book.left++; 191 cout << "编号为" << num << "的图书已归还，下面是这本书的现存信息：" << endl; 192 old_book.print(); 193 total++; 194 } 195 void save(const char filename[20]) 196 { 197 writeFile(filename); 198 } 199 };