简介:并未封装成类,功能也仅实现了增删改查。数据为txt,格式:学号(long) 姓名(string) 总分(int)
学生信息结构体
struct Student { long m_id; string m_name; int m_score; };
节点结构体
struct Node { Student data; Node* next; Node() { next = nullptr; } };
读取data.txt获取数据
Node* ReadInformation(Node* root) { if (!root) root = new Node();//防止输入一个未初始化的指针 Node* p = root; Node* q = nullptr;//去掉最后的空指针 ifstream in("data.txt"); long id; string name; int score; while (!in.eof()) { in >> id >> name >> score; p->data.Set(id, name, score); p->next = new Node(); q = p; p = p->next; } q->next = nullptr; delete p; p = nullptr; in.close(); return root;//返回首指针 }
输出全部信息
void Print(Node* root) { if (!root) return; Node* p = root; cout << setw(6) << "ID" << setw(8) << "Name" << setw(6) << "Score\n"; while (p) { cout << setw(6) << p->data.m_id << setw(8) << p->data.m_name << setw(6) << p->data.m_score << endl; p = p->next; } cout << endl; }
四个基本功能:增删改查
增Add:首端插入
Node* Add(Node* root, const Student& stu) { Node* p = new Node(); p->data = stu; p->next = root; return p; }删Delete:
//遍历 删除stu对应节点,然后返回头指针 Node* Delete(Node* root, const Student& stu) { if (!root) { cout << "No information to delete.\n"; return root; } Node* q = root; Node* p = q->next; //检查第一个 if (q->data == stu) { root = root->next; delete q; q = nullptr; return root; } while (p) { if (p->data == stu) { q->next = p->next; delete p; p = nullptr; return root; } } cout << "No such information to delete.\n"; return root; }
改Modify:
//找到index:从0开始(并非id) 对应的节点,输入修改后的信息,修改,然后返回头指针 void Modify(Node* root, const int& index) { if (!root) { cout << "There is no information to modify.\n"; return; } Node* p = root; int i(0); while (p) { if (i == index) { cout<<"Information;"<< p->data.m_id << setw(8) << p->data.m_name << setw(6) << p->data.m_score << endl; long id; string name; int score; char c; cout << "New:"; cin >> id >> name >> score; cout << "Are you sure to modify the information?<y/n> \nEnter:"; cin >> c; if (c == 'Y' || c == 'y') { p->data.Set(id, name, score); return; } else return; } p = p->next; ++i; } cout << "The index:" << index << " is too big.\n" << "There are " << i+1 << " students.\n"; }
查Find:分为id、name、score range三种查找
Node* Find(Node* root,const int& cho) { if (!root) { cout << "The linklist is empty.\n"; return nullptr; } long id; string name; int sco1, sco2; Node* p = nullptr; switch (cho) { case 1: cout << "Please input Id:"; cin >> id; p=FindById(root,id); break; case 2: cout << "Please input Name:"; cin >> name; p=FindByName(root,name); break;
case 3: cout << "Please input Score's range:"; cin >> sco1 >> sco2; p = FindByScore(root, sco1, sco2);
break; default: break; }
if (!p) cout << "Not found.\n"; return p; }
Node* FindById(Node* root,const long& id) { Node* p = root; while (p) { if (p->data.m_id == id) { cout << setw(6) << p->data.m_id << setw(8) << p->data.m_name << setw(6) << p->data.m_score << endl; return p; } p = p->next; } return nullptr; } Node* FindByName(Node* root,const string& name) { Node* p = root; Node* res=nullptr; int count(0); while (p) { if (p->data.m_name == name) { cout << setw(6) << p->data.m_id << setw(8) << p->data.m_name << setw(6) << p->data.m_score << endl; ++count; if (count == 1) res = p; } p = p->next; } return res; } Node* FindByScore(Node* root,const int& sco1,const int& sco2) { if (sco1 > sco2) { cout << "Error input.\n"; return nullptr; } Node* p = root; Node* res = nullptr;
int count(0); while (p) { if (p->data.m_score >= sco1 && p->data.m_score <= sco2) { cout << setw(6) << p->data.m_id << setw(8) << p->data.m_name << setw(6) << p->data.m_score << endl; ++count; if (count == 1) res = p; } p = p->next; } return res; }
测试:main.cpp
bool IsUnique(Node* root, const long& id) { if (!root) return true; Node* p = root; while (p) { if (p->data.m_id == id) { return false; } p = p->next; } return true; }
Node* link=nullptr; int main() { link = ReadInformation(link); { cout << "0.Exit\n"; cout << "1.Add\n"; cout << "2.Delete\n"; cout << "3.Modify\n"; cout << "4.Find\n"; cout << "5.Print\n\n\n"; } int cho; int cho2; do{ cout << "Enter: "; cin >> cho;
Student s; int index;
switch (cho) { case 0:break; case 1: cout << "Information:"; cin >> s.m_id >> s.m_name >> s.m_score; //check id avoid the same id if (!IsUnique(link, s.m_id)) { cout << "Id has existed.\n"; break; } link = Add(link, s); break; case 2: cout << "Information:"; cin >> s.m_id >> s.m_name >> s.m_score; link = Delete(link, s); break; case 3: cout << "Index:"; cin >> index; Modify(link, index); break; case 4: cout << "1.Find by Id\n" << "2.Find by Name\n" << "3.Find by Score's range\n" << "Enter:"; cin >> cho2; Find(link, cho2); break; case 5: Print(link); break; } } while (cho); system("pause"); return 0; }
运行截图: