【练手小项目】简易通讯录：单链表实现
简易通讯录：单链表实现
结构描述：
#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;
class PeoNode {
private:
string name;
string sex;
int age;
string tele;
string addr;
PeoNode * next;
//Provide Contact access;
friend class Contact;
};
class Contact {
public:
//初始化通讯录信息
void initContact();
//判空
bool isEmpty();
//添加联系人
void addPeople();
//打印通讯录信息
void printContact();
//根据联系人的姓名删除联系人
void deleteByName(string & name);
//根据姓名查找联系人
PeoNode * searchByName(string & name);
//根据姓名修改联系人的信息
void modifyByName(string & name);
//分配节点
PeoNode * buyNode();
//销毁
void makeEmpty();
private:
PeoNode * head;
};
初始化通讯录
把链表的头指针置空：
void Contact::init() {
head = nullptr;
}
添加联系人
使用头插法添加联系人至链表中：
void Contact::addPeople() {
PeoNode * newNode = buyNode();
newNode->next = head;
head = newNode;
}
分配节点
根据用户输入创建一个联系人节点，并返回节点。
PeoNode * Contact::buyNode() {
//分配节点并判断是否成功
PeoNode * newNode = new PeoNode();
if (newNode == nullptr) {
cout << "New Failed!\n";
exit(-1);
}
//输入信息
cout << "Please enter name:> "; getline(cin, newNode->name);
cout << "Please enter sex:> "; getline(cin, newNode->sex);
//cin.ignore()方法忽略掉在读取整数后可能残留在输入缓冲区中的换行符
cout << "Please enter age:> "; cin >> newNode->age; cin.ignore();
cout << "Please enter telephone:> "; getline(cin, newNode->tele);
cout << "Please enter address:> "; getline(cin, newNode->addr);
newNode->next = nullptr;
return newNode;
}
打印通讯录
-
表空：不允许操作
-
非空：遍历并打印每一个元素
void Contact::printContact() {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
//表头
cout << "name" << "\t"
<< "sex" << "\t"
<< "age" << "\t"
<< "tele" << "\t"
<< "addr" << "\n";
PeoNode * cur = head;
while (cur != nullptr) {
cout << cur->name << "\t"
<< cur->sex << "\t"
<< cur->age << "\t"
<< cur->tele << "\t"
<< cur->addr << "\n";
cur = cur->next;
}
}
查找联系人
根据联系人的名字查找。
- 表空：报错
- 非空：遍历查找，找到第一个名字匹配的，并返回节点指针，若到表尾还没有找到，则联系人不存在
PeoNode * Contact::searchByName(string & name) {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
PeoNode * cur = head;
while (cur != nullptr) {
if (cur->name == name) {
return cur;
}
//向后遍历
cur = cur->next;
}
//没找到返回nullptr
return nullptr;
}
删除联系人
- 根据名字查找
- 找到：删除
- 找不到：报告不存在
void Contact::deleteByName(string & name) {
PeoNode * ret = searchByName(name);
if (ret == nullptr) {
cout << "People is Not Exist!\n";
exit(-1);
}
//调整链表的关系
PeoNode * cur = head;
while (cur->next != ret) {
cur = cur->next;
}
cur->next = ret->next;
//释放节点
delete ret;
ret = nullptr;
}
修改联系人信息
- 根据名字查找
- 查找成功：修改
- 查找失败：返回错误
void Contact::modifyByName(string & name) {
PeoNode * ret = searchByName(name);
if (ret == nullptr) {
cout << "Search Failed!\n";
exit(-1);
}
//输入信息
cout << "Please enter name:> "; getline(cin, ret->name);
cout << "Please enter sex:> "; getline(cin, ret->sex);
//cin.ignore()方法忽略掉在读取整数后可能残留在输入缓冲区中的换行符
cout << "Please enter age:> "; cin >> ret->age; cin.ignore();
cout << "Please enter telephone:> "; getline(cin, ret->tele);
cout << "Please enter address:> "; getline(cin, ret->addr);
}
销毁
- 表空：返回错误
- 非空：一直头删，直至表空
void Contact::makeEmpty() {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
while (!isEmpty()) {
cout << head->name;
//头删
PeoNode * tmp = head;
head = head->next;
free(tmp);
tmp = nullptr;
cout << "has been poped!\n";
}
cout << "Make Empty Successfully!\n";
}
综上
Contact.hpp
#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;
class PeoNode {
private:
string name;
string sex;
int age;
string tele;
string addr;
PeoNode * next;
//Provide Contact access;
friend class Contact;
};
class Contact {
public:
//初始化通讯录信息
void initContact();
//判空
bool isEmpty();
//添加联系人
void addPeople();
//打印通讯录信息
void printContact();
//根据联系人的姓名删除联系人
void deleteByName(string & name);
//根据姓名查找联系人
PeoNode * searchByName(string & name);
//根据姓名修改联系人的信息
void modifyByName(string & name);
//分配节点
PeoNode * buyNode();
//销毁
void makeEmpty();
private:
PeoNode * head;
};
Contact.cpp
#include "Contact.hpp"
void Contact::initContact() {
head = nullptr;
}
bool Contact::isEmpty() {
return head == nullptr;
}
void Contact::addPeople() {
PeoNode * newNode = buyNode();
newNode->next = head;
head = newNode;
}
PeoNode * Contact::buyNode() {
//分配节点并判断是否成功
PeoNode * newNode = new PeoNode();
if (newNode == nullptr) {
cout << "New Failed!\n";
exit(-1);
}
//输入信息
cout << "Please enter name:> "; getline(cin, newNode->name);
cout << "Please enter sex:> "; getline(cin, newNode->sex);
//cin.ignore()方法忽略掉在读取整数后可能残留在输入缓冲区中的换行符
cout << "Please enter age:> "; cin >> newNode->age; cin.ignore();
cout << "Please enter telephone:> "; getline(cin, newNode->tele);
cout << "Please enter address:> "; getline(cin, newNode->addr);
newNode->next = nullptr;
return newNode;
}
void Contact::printContact() {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
//表头
cout << "name" << "\t"
<< "sex" << "\t"
<< "age" << "\t"
<< "tele" << "\t"
<< "addr" << "\n";
PeoNode * cur = head;
while (cur != nullptr) {
cout << cur->name << "\t"
<< cur->sex << "\t"
<< cur->age << "\t"
<< cur->tele << "\t"
<< cur->addr << "\n";
cur = cur->next;
}
}
PeoNode * Contact::searchByName(string & name) {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
PeoNode * cur = head;
while (cur != nullptr) {
if (cur->name == name) {
return cur;
}
//向后遍历
cur = cur->next;
}
//没找到返回nullptr
return nullptr;
}
void Contact::deleteByName(string & name) {
PeoNode * ret = searchByName(name);
if (ret == nullptr) {
cout << "People is Not Exist!\n";
exit(-1);
}
//调整链表的关系
PeoNode * cur = head;
while (cur->next != ret) {
cur = cur->next;
}
cur->next = ret->next;
//释放节点
delete ret;
ret = nullptr;
}
void Contact::modifyByName(string & name) {
PeoNode * ret = searchByName(name);
if (ret == nullptr) {
cout << "Search Failed!\n";
exit(-1);
}
//输入信息
cout << "Please enter name:> "; getline(cin, ret->name);
cout << "Please enter sex:> "; getline(cin, ret->sex);
//cin.ignore()方法忽略掉在读取整数后可能残留在输入缓冲区中的换行符
cout << "Please enter age:> "; cin >> ret->age; cin.ignore();
cout << "Please enter telephone:> "; getline(cin, ret->tele);
cout << "Please enter address:> "; getline(cin, ret->addr);
}
void Contact::makeEmpty() {
if (isEmpty()) {
cout << "List Is Empty!\n";
exit(-1);
}
while (!isEmpty()) {
cout << head->name;
//头删
PeoNode * tmp = head;
head = head->next;
free(tmp);
tmp = nullptr;
cout << "has been poped!\n";
}
cout << "Make Empty Successfully!\n";
}
踩坑
C++处理字符串输入用 std::getline() 方法
C++中 new 关键字为对象分配空间，并返回该对象的指针。