数据结构课程设计，用线性表做一个通讯录管理系统

求一个注释，帮忙解析以下代码

#include<iostream>
#include<string>
#include<cstdlib>
#define MAX 2000
using namespace std;
//通讯录管理系统

//设计联系人结构体
struct Person {
	string m_Name;
	int m_Sex;
	int m_Age;
	string m_Phone;
	string m_Addr;
};

//设计通讯录结构体
struct Addressbooks {
	//通讯录中保存的联系人数组
	struct Person personArray[MAX];
	
	//通讯录中当前记录的联系人个数
	int m_Size;
};

//添加联系人
void addPerson(Addressbooks* abs) {
	//判满
	if (abs->m_Size == MAX) {
		cout << "通讯录已满" << endl;
		return;
	}
	else {

		//姓名
		string name;
		cout << "请输入姓名" << endl;
		cin >> name;
		abs->personArray[abs->m_Size].m_Name = name;

		//性别
		cout << "请输入性别" << endl;
		cout << "1——男" << endl;
		cout << "2——女" << endl;
		int sex = 0;

		while (true) {
			cin >> sex;
			if (sex == 1 || sex == 2) {
				abs->personArray[abs->m_Size].m_Sex = sex;
				break;
			}
			cout << "输入有误，重新输入" << endl;
		}

		//年龄
		cout << "请输入年龄" << endl;
		int age = 0;
		cin >> age;
		abs->personArray[abs->m_Size].m_Age = age;

		//电话
		cout << "请输入电话" << endl;
		string phone;
		cin>> phone;
		abs->personArray[abs->m_Size].m_Phone = phone;

		//住址
		cout << "请输入住址" << endl;
		string address;
		cin>> address;
		abs->personArray[abs->m_Size].m_Addr = address;

		//更新通讯录人数
		abs->m_Size++;

		cout << "更新成功" << endl;
		system("pause");
		system("cls");		//清屏操作
	}
}

//显示联系人
void showPerson(Addressbooks* abs) {
	//判空
	if (abs->m_Size == 0) {
		cout << "当期记录为空" << endl;
	}
	else {
		for (int i = 0; i < abs->m_Size; i++) {
			cout << "姓名：" << abs->personArray[i].m_Name<<"\t";
			cout << "性别：" << (abs->personArray[i].m_Sex == 1 ? "男":"女")<< "\t";
			cout << "年龄：" << abs->personArray[i].m_Age << "\t";
			cout << "电话：" << abs->personArray[i].m_Phone << "\t";
			cout << "住址：" << abs->personArray[i].m_Addr << endl;
		}
	}
	system("pause");
	system("cls");		//清屏操作
}

//检测联系人是否存在
int isExist(Addressbooks* abs, string name) {
	for (int i = 0; i < abs->m_Size; i++) {
		//找到用户姓名了
		if (abs->personArray[i].m_Name == name) {
			return i;
		}
	}
	return -1;
}

//删除联系人
void deletePerson(Addressbooks* abs) {
	cout << "请输入要删除的联系人" << endl;

	string name;
	cin >> name;
	int ret = isExist(abs, name);

	if (ret != -1) {
		for (int i = ret; i < abs->m_Size; i++) {
			abs->personArray[i] = abs->personArray[i + 1];
		}
		abs->m_Size--;
		cout << "删除成功" << endl;
	}
	else {
		cout << "查无此人" << endl;
	}

	system("pause");
	system("cls");		//清屏操作
}

//查找联系人
void findPersin(Addressbooks* abs) {
	cout << "请输入要查找的联系人" << endl;
	string name;
	cin >> name;

	int ret = isExist(abs, name);

	if (ret != -1) {
		cout << "姓名：" << abs->personArray[ret].m_Name << "\t";
		cout << "性别：" << (abs->personArray[ret].m_Sex == 1 ? "男" : "女") << "\t";
		cout << "年龄：" << abs->personArray[ret].m_Age << "\t";
		cout << "电话：" << abs->personArray[ret].m_Phone << "\t";
		cout << "住址：" << abs->personArray[ret].m_Addr << endl;
	}
	else {
		cout << "查无此人" << endl;
	}

	system("pause");
	system("cls");		//清屏操作
}

//修改联系人
void modifyRerson(Addressbooks* abs) {
	cout << "请输入要修改的联系人" << endl;
	string name;
	cin >> name;

	int ret = isExist(abs, name);

	if (ret != -1) {
		//姓名
		string name;
		cout << "请输入姓名" << endl;
		cin >> name;
		abs->personArray[ret].m_Name = name;

		//年龄
		int age;
		cout << "请输入年龄" << endl;
		cin >> age;
		abs->personArray[ret].m_Age = age;

		//电话
		int phone;
		cout << "请输入电话" << endl;
		cin >> phone;
		abs->personArray[ret].m_Phone = phone;

		//住址
		string address;
		cout << "请输入住址" << endl;
		cin >> address;
		abs->personArray[ret].m_Addr = address;

		cout << "修改成功" << endl;
	}
	else {
		cout << "查无此人" << endl;
	}
	system("pause");
	system("cls");		//清屏操作
}

//清空联系人
void cleanPerson(Addressbooks* abs) {
	abs->m_Size = 0;		//只需要将联系人数量置为0，做逻辑清空就可以了
	cout << "通讯录已清空"<< endl;
}

//菜单界面
void showMenu() {
	cout << "1. 添加联系人" << endl;
	cout << "2. 显示联系人" << endl;
	cout << "3. 删除联系人" << endl;
	cout << "4. 查找联系人" << endl;
	cout << "5. 修改联系人" << endl;
	cout << "6. 清空联系人" << endl;
	cout << "0. 退出通讯录" << endl;
}


int main() {

	//创建通讯录
	Addressbooks abs;
	//初始化通讯录当前人员个数
	abs.m_Size = 0;
	int select = 0;		//创建用户选择输入的变量

	while (true) {
		// 菜单界面
		showMenu();

		cin >> select;
		switch (select) {
		case 1:		//1. 添加联系人
			addPerson(&abs);	//利用地址传递修改实参
			break;
		case 2:		//2. 显示联系人
			showPerson(&abs);
			break;
		case 3:		//3. 删除联系人
		//{
		//	cout << "请输入删除联系人姓名：" << endl;
		//	string name;
		//	cin >> name;

		//	if (isExist(&abs, name) == -1) {
		//		cout << "查无此人" << endl;
		//	}
		//	else {
		//		cout << "找到此人" << endl;
		//	}
		//}
			deletePerson(&abs);
			break;
		case 4:		//4. 查找联系人
			findPersin(&abs);
			break;
		case 5:		//5. 修改联系人
			modifyRerson(&abs);
			break;
		case 6:		//6. 清空联系人
			cleanPerson(&abs);
			break;
		case 0:		//0. 退出通讯录
			cout << "欢迎下次使用" << endl;
			system("pause");
			return 0;
			break;
		defult:
			break;
		}
	}

	system("pause");
	return 0;
}