用户登录系统的模拟C++

用户登录系统的模拟【问题描述】在登录服务器系统时，都需要验证用户名和密码，如telnet远程登录服务器。

用户输入用户名和密码后，服务器程序会首先验证用户信息的合法性。

由于用户信息的验证频率很高，系统有必要有效地组织这些用户信息，从而快速查找和验证用户。

另外，系统也会经常会添加新用户、删除老用户和更新用户密码等操作，因此，系统必须采用动态结构，在添加、删除或更新后，依然能保证验证过程的快速。

请采用相应的数据结构模拟用户登录系统，其功能要求包括用户登录、用户密码更新、用户添加和用户删除等。

【基本要求】1.要求自己编程实现二叉树结构及其相关功能，以存储用户信息，不允许使用标准模板类的二叉树结构和函数。

同时要求根据二叉树的变化情况，进行相应的平衡操作，即A VL 平衡树操作，四种平衡操作都必须考虑。

测试时，各种情况都需要测试，并附上测试截图；2.要求采用类的设计思路，不允许出现类以外的函数定义，但允许友元函数。

主函数中只能出现类的成员函数的调用，不允许出现对其它函数的调用。

3.要求采用多文件方式：.h文件存储类的声明，.cpp文件存储类的实现，主函数main存储在另外一个单独的cpp文件中。

如果采用类模板，则类的声明和实现都放在.h文件中。

4.不强制要求采用类模板，也不要求采用可视化窗口；要求源程序中有相应注释；5.要求测试例子要比较详尽，各种极限情况也要考虑到，测试的输出信息要详细易懂，表明各个功能的执行正确；6.要求采用Visual C++ 6.0及以上版本进行调试；【实现提示】1.用户信息(即用户名和密码)可以存储在文件中，当程序启动时，从文件中读取所有的用户信息，并建立合适的查找二叉树；2.验证过程时，需要根据登录的用户名，检索整个二叉树，找到匹配的用户名，进行验证；更新用户密码时，也需要检索二叉树，找到匹配项后进行更新，同时更新文件中存储的用户密码。

3.添加用户时，不仅需要在文件中添加，也需要在二叉树中添加相应的节点；删除用户时，也是如此；仅供参考目录Node.h (3)Tree.h (4)Tree.cpp (5)tree::~tree(void) (5)int tree::depth(node *t) (6)void tree::add(){ (6)void tree::delete_user(){ (7)void tree::newpassword(){ (7)void tree::login(){ (8)void tree::travelsee(node *p){ (8)void tree::insert(int n, string p) (9)void tree::deleteNode(node *t){ (9)//该节点无子节点 (9)//该节点只有左节点 (10)//该节点只有右节点 (10)//该节点有两个子节点 (11)//平衡 (11)void tree::LL(node *B) //B为中间节点 (12)void tree::RR(node *B) (13)void tree::LR(node *C)//最下面一个节点 (13)void tree::RL(node *C) (14)void tree::balance(node *C){ (14)Main.cpp (15)Data.txt (16)Node.h#ifndef NODE#define NODE#include <iostream>#include <string>using namespace std;class node{public:node(int n = NULL, string p = NULL, node *l = NULL, node *r = NULL, node *pa =NULL):name(n),password(p),left(l),right(r),parent(pa){}node *left;node *right;node *parent;int balancefactor;int getName(){return name;}string getpassword(){return password;}void setpassword(string s){password = s;}private:int name;string password;};#endifTree.h#include "node.h"#include <fstream>#include <iomanip>#include <queue>using namespace std;class tree{public:tree():root(NULL),treeSize(0){}~tree();//将树中信息写入文件void add();//添加用户void delete_user();//删除用户void newpassword();//更改密码void login();//登录void insert(int n,string p);//插入int depth(node *t);//高度void deleteNode(node *t);//删除节点void LL(node* t);//左旋void RR(node* t);//右旋void LR(node* t);//左-右旋void RL(node* t);//右-左旋void balance(node *t);//进行平衡void travelsee(node *t);//中序遍历入队列int len(node* t){int i = 0;while(t!=root){t = t->parent;i += 4;}return i;}void release(node* t){//释放if(t!=NULL){release(t->left);release(t->right);delete t;}}private:node *root;int treeSize;queue<int> q1;queue<string> q2;};Tree.cpp#include "tree.h"tree::~tree(void){ofstream f("data.txt",ios::out);node *p = root;if(treeSize)while(p->right)p = p->right;else return;int i = p->getName();travelsee(root);while(!q1.empty()){if(q1.front() == i)f << q1.front() << ' ' << q2.front();elsef << q1.front() << ' ' << q2.front() << endl;q1.pop();q2.pop();}f.close();release(root);system("pause");}int tree::depth(node *t){int leftdepth, rightdepth, valdepth;if(t == NULL)valdepth = -1;else{leftdepth = depth(t->left);rightdepth = depth(t->right);valdepth = 1 + (leftdepth > rightdepth ? leftdepth : rightdepth);}return valdepth;}void tree::add(){string t;if(!treeSize){cout << "分配的账号为：1" << endl;cout << "请输入密码：";cin >> t;insert(1,t);cout << endl;cout << "添加成功" << endl;return;}int i;node *p = root;while(p->right){p = p->right;}i = p->getName();i++;cout << "分配的账号为：" << i << endl;cout << "请输入密码：";cin >> t;insert(i,t);cout << endl;cout << "添加成功" << endl;}void tree::delete_user(){int i;string t;cout << "输入要删除的账号：";cin >> i;node *p = root;while(p){if(p->getName() == i) {cout << "输入密码：";cin >> t;if(t == p->getpassword()){deleteNode(p);cout << "已删除" << endl;}else cout << "密码错误" << endl;return;}else if(i > p->getName())p = p->right;else p = p->left;}cout << "未找到该用户" << endl;}void tree::newpassword(){string t;int i;cout << "输入要修改密码的账号：";cin >> i;node *p = root;while(p){if(p->getName() == i) {cout << "输入原密码：";cin >> t;if(t == p->getpassword()){cout << "输入新密码：";cin >> t;p->setpassword(t);cout << "修改成功" << endl;}else cout << "原密码错误" << endl;return;}else if(i > p->getName())p = p->right;else p = p->left;}cout << "未找到该用户" << endl;}void tree::login(){int i;string t;cout << "账号：";cin >> i;node *p = root;while(p){if(p->getName() == i) {cout << "密码：";cin >> t;if(t == p->getpassword())cout << "登录成功" << endl;elsecout << "登录失败" << endl;return;}else if(i > p->getName())p = p->right;else p = p->left;}cout << "未找到该用户" << endl;}void tree::travelsee(node *p){if(p->left) travelsee(p->left);cout << setw(len(p)) << " " << p->getName() << endl;q1.push(p->getName());q2.push(p->getpassword());if(p->right) travelsee(p->right);}void tree::insert(int n, string p){//插入节点node *t = root, *t1;if(!treeSize)root = new node(n,p,NULL,NULL,NULL);else{while(t){t1 = t;if(n == t->getName()){cout << "已存在此账号" << endl; return;}else if(n > t->getName())t = t->right;else if(n < t->getName())t = t->left;}if(n > t1->getName())t = t1->right = new node(n,p,NULL,NULL,t1);else if(n < t1->getName())t = t1->left = new node(n,p,NULL,NULL,t1);}treeSize++;balance(t);}void tree::deleteNode(node *t){//该节点无子节点node *t1 = t;bool flag = false;if(t == root) flag = true;if(!t->left && !t->right){t1 = t->parent;if(!t->parent) delete root;else if(t == t->parent->right){t->parent->right = NULL;}else if(t == t->parent->left){t->parent->left = NULL;}delete t;treeSize--;}//该节点只有左节点else if(t->left && !t->right){if(t == t->parent->right){t->parent->right = t->left;t->left->parent = t->parent;t1 = t->parent->right;}else if(t == t->parent->left){t->parent->left = t->left;t->left->parent = t->parent;t1 = t->parent->left;}delete t;treeSize--;}//该节点只有右节点else if(!t->left && t->right){if(t == t->parent->right){t->parent->right = t->right;t->right->parent = t->parent;t1 = t->parent->right;}else if(t == t->parent->left){t->parent->left = t->right;t->right->parent = t->parent;t1 = t->parent->left;}delete t;treeSize--;}//该节点有两个子节点//取右子树最左节点替代else{t1 = t->right;while(t1->left)t1 = t1->left;if(!flag){if(t == t->parent->right )t->parent->right = t1;elset->parent->left = t1;}if(t1->getName() == t->right->getName()){t1->parent = t->parent;t->left->parent = t1;t1->left = t->left;}else{t1->parent->left = t1->right;if(t1->right)t1->right->parent = t1->parent;t1->parent = t->parent;t->left->parent = t1;t->right->parent = t1;t1->left = t->left;t1->right = t->right;}delete t;treeSize--;if(flag)root = t1;}//平衡while(t1){t1->balancefactor = depth(t1->right) - depth(t1->left);if(t1->balancefactor < 2 && t1->balancefactor > -2)break;else if(t1->balancefactor > 0){if(t1->balancefactor > 2)t1 = t1->right;else{t1 = t1->right;t1->balancefactor = depth(t1->right) - depth(t1->left);if(t1->balancefactor > 0)balance(t1->right);else balance(t1->left);break;}}else{if(t1->balancefactor < -2)t1 = t1->left;else{t1 = t1->left;t1->balancefactor = depth(t1->right) - depth(t1->left);if(t1->balancefactor > 0)balance(t1->right);else balance(t1->left);break;}}}}void tree::LL(node *B) //B为中间节点{node *A = B->parent;bool flag = false;if(A == root) flag = true;if(A->parent != NULL){if(A->parent->left == A)A->parent->left = B;elseA->parent->right = B;}B->parent = A->parent;A->parent = B;A->right = B->left;if(B->left)B->left->parent = A;B->left = A;if(flag) root = B;}void tree::RR(node *B){node *A = B->parent;bool flag = false;if(A == root) flag = true;if(A->parent != NULL){if(A->parent->left == A)A->parent->left = B;elseA->parent->right = B;}B->parent = A->parent;A->parent = B;A->left = B->right;if(B->right)B->right->parent = A;B->right = A;if(flag) root = B;}void tree::LR(node *C)//最下面一个节点{node *B = C->parent;if(B->parent->right == B)B->parent->right = C;elseB->parent->left = C;C->parent = B->parent;B->parent = C;B->right = C->left;C->left = B;RR(C);}void tree::RL(node *C){node *B = C->parent;if(B->parent->right == B)B->parent->right = C;elseB->parent->left = C;C->parent = B->parent;B->parent = C;B->left = C->right;C->right = B;LL(C);}void tree::balance(node *C){//C为新插入节点if(treeSize <= 2 || treeSize == 4)return;else if(treeSize == 3 && C->parent->parent == NULL)return;node *A = C->parent->parent, *B = C->parent;A->balancefactor = depth(A->right) - depth(A->left);if(A->balancefactor < 0) A->balancefactor = - A->balancefactor;if(A->balancefactor == 2){if(B == A->right){if(C == B->right) LL(B);else RL(C);}else {if(C == B->right) LR(C);else RR(B);}}while(A->balancefactor != 2 && A->parent){C = B;B = A;A = A->parent;A->balancefactor = depth(A->right) - depth(A->left);if(A->balancefactor < 0) A->balancefactor = - A->balancefactor;if(A->balancefactor == 2){if(B == A->right){if(C == B->right) LL(B);else RL(C);}else {if(C == B->right) LR(C);else RR(B);}continue;}}}Main.cpp#include <iostream>#include "tree.h"using namespace std;int main(){ifstream f("data.txt");tree *p = new tree();int i;string t;while(!f.eof()){f >> i >> t;if(i<0) break;p->insert(i,t);}f.close();while(1){cout << "用户登录模拟系统" << endl;cout << "1、登录" << endl;cout << "2、修改密码" << endl;cout << "3、删除账号" << endl;cout << "4、注册账号" << endl;cout << "0、退出" << endl;cout << "输入编号（非0退出操作失效）：";cin >> i;switch(i){case 0:p->~tree(); return 0;case 1:system("cls");p->login(); cout << endl; continue;case 2:system("cls");p->newpassword(); cout << endl; continue;case 3:system("cls");p->delete_user(); cout << endl; continue;case 4:system("cls");p->add(); cout << endl; continue;}}system("pause");return 0;}Data.txt1 h2 h3 h4 h5 h6 h7 h8 h9 h10 h11 h12 h13 h14 h15 h。