实验任务1
（1）代码部分
1 //button.hpp
2 #pragma once
3
4 #include <iostream>
5 #include <string>
6
7 using std::string;
8 using std::cout;
9
10 // 按钮类
11 class Button {
12 public:
13 Button(const string &text);
14 string get_label() const;
15 void click();
16
17 private:
18 string label;
19 };
20
21 Button::Button(const string &text): label{text} {
22 }
23
24 inline string Button::get_label() const {
25 return label;
26 }
27
28 void Button::click() {
29 cout << "Button '" << label << "' clicked\n";
30 }
31 //winodw.hpp
32 #pragma once
33 #include "button.hpp"
34 #include <vector>
35 #include <iostream>
36
37 using std::vector;
38 using std::cout;
39 using std::endl;
40
41 // 窗口类
42 class Window{
43 public:
44 Window(const string &win_title);
45 void display() const;
46 void close();
47 void add_button(const string &label);
48
49 private:
50 string title;
51 vector<Button> buttons;
52 };
53
54 Window::Window(const string &win_title): title{win_title} {
55 buttons.push_back(Button("close"));
56 }
57
58 inline void Window::display() const {
59 string s(40, '*');
60
61 cout << s << endl;
62 cout << "window title: " << title << endl;
63 cout << "It has " << buttons.size() << " buttons: " << endl;
64 for(const auto &i: buttons)
65 cout << i.get_label() << " button" << endl;
66 cout << s << endl;
67 }
68
69 void Window::close() {
70 cout << "close window '" << title << "'" << endl;
71 buttons.at(0).click();
72 }
73
74 void Window::add_button(const string &label) {
75 buttons.push_back(Button(label));
76 }
77 //task1.cpp
78 #include "window.hpp"
79 #include <iostream>
80
81 using std::cout;
82 using std::cin;
83
84 void test() {
85 Window w1("new window");
86 w1.add_button("maximize");
87 w1.display();
88 w1.close();
89 }
90
91 int main() {
92 cout << "用组合类模拟简单GUI:\n";
93 test();
94 }
View Code
（2）运行结果
（3）
问题一：
自定义了两个类：Window和Button；使用了标准库中的string类和vector类；Button类中使用了string类，Window类中使用了Button类，string类和vector类；
问题二：
不适合再添加const或inline，剩下的函数不会修改类内成员数据无需加const，inline使用太多会使代码膨胀，并且剩下函数执行时间与调用时间差别不大，使用inline收益小；
问题三:
创建一个长度为40的‘*’号字符串s;
实验任务2
（1）代码部分
1 //task2.cpp
2 #include <iostream>
3 #include <vector>
4
5 using namespace std;
6
7 void output1(const vector<int> &v) {
8 for(auto &i: v)
9 cout << i << ", ";
10 cout << "\b\b \n";
11 }
12
13 void output2(const vector<vector<int>> v) {
14 for(auto &i: v) {
15 for(auto &j: i)
16 cout << j << ", ";
17 cout << "\b\b \n";
18 }
19 }
20
21 void test1() {
22 vector<int> v1(5, 42);
23 const vector<int> v2(v1);
24
25 v1.at(0) = -999;
26 cout << "v1: "; output1(v1);
27 cout << "v2: "; output1(v2);
28 cout << "v1.at(0) = " << v1.at(0) << endl;
29 cout << "v2.at(0) = " << v2.at(0) << endl;
30 }
31
32 void test2() {
33 vector<vector<int>> v1{{1, 2, 3}, {4, 5, 6, 7}};
34 const vector<vector<int>> v2(v1);
35
36 v1.at(0).push_back(-999);
37 cout << "v1: \n"; output2(v1);
38 cout << "v2: \n"; output2(v2);
39
40 vector<int> t1 = v1.at(0);
41 cout << t1.at(t1.size()-1) << endl;
42
43 const vector<int> t2 = v2.at(0);
44 cout << t2.at(t2.size()-1) << endl;
45 }
46
47 int main() {
48 cout << "测试1:\n";
49 test1();
50
51 cout << "\n测试2:\n";
52 test2();
53 }
View Code
（2）运行结果
（3）
问题一：
创建一个长度为5的整型vector数组：v1，将所有元素初始化为42；以v1为原型复制构造v2；将v1第一个元素改为-999；
问题二:
创建一个二维的vector数组v1，元素类型为int并初始化；以v1为原型复制构造v2；在v1的第一行后面添加元素-999；
问题三：
将v1的第一行元素复制给t1；打印出t1的最后一个元素；将v2的第一行元素复制给t2；打印出t2的最后一个元素；
问题四：
vector的复制构造函数是深复制；不需要；
实验任务三
（1）代码部分
1 //vectorInt.hpp
2 #pragma once
3
4 #include <iostream>
5 #include <cassert>
6
7 using std::cout;
8 using std::endl;
9
10 // 动态int数组对象类
11 class vectorInt{
12 public:
13 vectorInt(int n);
14 vectorInt(int n, int value);
15 vectorInt(const vectorInt &vi);
16 ~vectorInt();
17
18 int& at(int index);
19 const int& at(int index) const;
20
21 vectorInt& assign(const vectorInt &v);
22 int get_size() const;
23
24 private:
25 int size;
26 int *ptr; // ptr指向包含size个int的数组
27 };
28
29 vectorInt::vectorInt(int n): size{n}, ptr{new int[size]} {
30 }
31
32 vectorInt::vectorInt(int n, int value): size{n}, ptr{new int[size]} {
33 for(auto i = 0; i < size; ++i)
34 ptr[i] = value;
35 }
36
37 vectorInt::vectorInt(const vectorInt &vi): size{vi.size}, ptr{new int[size]} {
38 for(auto i = 0; i < size; ++i)
39 ptr[i] = vi.ptr[i];
40 }
41
42 vectorInt::~vectorInt() {
43 delete [] ptr;
44 }
45
46 const int& vectorInt::at(int index) const {
47 assert(index >= 0 && index < size);
48
49 return ptr[index];
50 }
51
52 int& vectorInt::at(int index) {
53 assert(index >= 0 && index < size);
54
55 return ptr[index];
56 }
57
58 vectorInt& vectorInt::assign(const vectorInt &v) {
59 delete[] ptr; // 释放对象中ptr原来指向的资源
60
61 size = v.size;
62 ptr = new int[size];
63
64 for(int i = 0; i < size; ++i)
65 ptr[i] = v.ptr[i];
66
67 return *this;
68 }
69
70 int vectorInt::get_size() const {
71 return size;
72 }
73 //task3.cpp
74 #include "vectorInt.hpp"
75 #include <iostream>
76
77 using std::cin;
78 using std::cout;
79
80 void output(const vectorInt &vi) {
81 for(auto i = 0; i < vi.get_size(); ++i)
82 cout << vi.at(i) << ", ";
83 cout << "\b\b \n";
84 }
85
86
87 void test1() {
88 int n;
89 cout << "Enter n: ";
90 cin >> n;
91
92 vectorInt x1(n);
93 for(auto i = 0; i < n; ++i)
94 x1.at(i) = i*i;
95 cout << "x1: "; output(x1);
96
97 vectorInt x2(n, 42);
98 vectorInt x3(x2);
99 x2.at(0) = -999;
100 cout << "x2: "; output(x2);
101 cout << "x3: "; output(x3);
102 }
103
104 void test2() {
105 const vectorInt x(5, 42);
106 vectorInt y(10, 0);
107
108 cout << "y: "; output(y);
109 y.assign(x);
110 cout << "y: "; output(y);
111
112 cout << "x.at(0) = " << x.at(0) << endl;
113 cout << "y.at(0) = " << y.at(0) << endl;
114 }
115
116 int main() {
117 cout << "测试1: \n";
118 test1();
119
120 cout << "\n测试2: \n";
121 test2();
122 }
View Code
（2）运行结果
（3）
问题一：
深复制；
问题二：
int & at(int index);中返回值类型改成int将不能正确运行const int & at(int index) const;中返回值类型改成int将可以正确运行；这是因为当返回值为int时，函数返回的是一个值的副本而不是引用，不能通过返回值来修改对象中的元素；将line18前面的const去掉对于测试代码没有安全隐患；
问题三：
将返回值改为vectorInt类型，返回的是整个数组的副本，会增加内存开销；
实验任务四
（1）代码部分
1 //Matrix.hpp
2 #pragma once
3
4 #include <iostream>
5 #include <cassert>
6
7 using std::cout;
8 using std::endl;
9
10 // 类Matrix的声明
11 class Matrix {
12 public:
13 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵, 初始值为value
14 Matrix(int n); // 构造函数，构造一个n*n的矩阵, 初始值为value
15 Matrix(const Matrix &x); // 复制构造函数， 使用已有的矩阵X构造
16 ~Matrix();
17
18 void set(const double *pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值
19 void clear(); // 把矩阵对象的值置0
20
21 const double& at(int i, int j) const; // 返回矩阵对象索引(i,j)的元素const引用
22 double& at(int i, int j); // 返回矩阵对象索引(i,j)的元素引用
23
24 int get_lines() const; // 返回矩阵对象行数
25 int get_cols() const; // 返回矩阵对象列数
26
27 void display() const; // 按行显示矩阵对象元素值
28
29 private:
30 int lines; // 矩阵对象内元素行数
31 int cols; // 矩阵对象内元素列数
32 double *ptr;
33 };
34
35 // 类Matrix的实现：待补足
36 // xxx
37 Matrix::Matrix(int n,int m):lines{n},cols{m},ptr{new double[n*m]}{};
38 Matrix::Matrix(int n):lines{n},cols{n},ptr{new double[n*n]}{};
39 Matrix::Matrix(const Matrix &x):lines{x.lines},cols{x.cols},ptr{new double[lines*cols]}{
40 for(int i=0;i<lines;i++)
41 for(int j=0;j<cols;j++){
42 ptr[i*cols+j]=x.ptr[i*cols+j];
43 }
44 }
45 Matrix::~Matrix(){
46 delete [] ptr;
47 }
48 void Matrix::set(const double *pvalue){
49 for(int i=0;i<lines;i++)
50 for(int j=0;j<cols;j++){
51 ptr[i*cols+j]=*pvalue;
52 pvalue++;
53 }
54 }
55 void Matrix::clear(){
56 for(int i=0;i<lines;i++)
57 for(int j=0;j<cols;j++){
58 ptr[i*cols+j]=0;
59 }
60 }
61 const double& Matrix::at(int i, int j) const{
62 return ptr[i*cols+j];
63 }
64 double& Matrix::at(int i, int j){
65 return ptr[i*cols+j];
66 }
67 int Matrix::get_lines() const{
68 return lines;
69 }
70 int Matrix::get_cols() const{
71 return cols;
72 }
73 void Matrix::display() const{
74 for(int i=0;i<lines;i++){
75 for(int j=0;j<cols-1;j++){
76 cout<<ptr[i*cols+j]<<',';
77 }
78 cout<<ptr[i*cols+cols-1]<<endl;
79 }
80 }
81
82 //task4.cpp
83 #include "matrix.hpp"
84 #include <iostream>
85 #include <cassert>
86
87 using std::cin;
88 using std::cout;
89 using std::endl;
90
91
92 const int N = 1000;
93
94 // 输出矩阵对象索引为index所在行的所有元素
95 void output(const Matrix &m, int index) {
96 assert(index >= 0 && index < m.get_lines());
97
98 for(auto j = 0; j < m.get_cols(); ++j)
99 cout << m.at(index, j) << ", ";
100 cout << "\b\b \n";
101 }
102
103
104 void test1() {
105 double x[1000] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
106
107 int n, m;
108 cout << "Enter n and m: ";
109 cin >> n >> m;
110
111 Matrix m1(n, m); // 创建矩阵对象m1, 大小n×m
112 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
113
114 Matrix m2(m, n); // 创建矩阵对象m1, 大小m×n
115 m2.set(x); // 用一维数组x的值按行为矩阵m1赋值
116
117 Matrix m3(2); // 创建一个2×2矩阵对象
118 m3.set(x); // 用一维数组x的值按行为矩阵m4赋值
119
120 cout << "矩阵对象m1: \n"; m1.display(); cout << endl;
121 cout << "矩阵对象m2: \n"; m2.display(); cout << endl;
122 cout << "矩阵对象m3: \n"; m3.display(); cout << endl;
123 }
124
125 void test2() {
126 Matrix m1(2, 3);
127 m1.clear();
128
129 const Matrix m2(m1);
130 m1.at(0, 0) = -999;
131
132 cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;
133 cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;
134 cout << "矩阵对象m1第0行: "; output(m1, 0);
135 cout << "矩阵对象m2第0行: "; output(m2, 0);
136 }
137
138 int main() {
139 cout << "测试1: \n";
140 test1();
141
142 cout << "测试2: \n";
143 test2();
144 }
View Code
（2）运行结果
实验任务五
（1）代码部分
1 #pragma once
2
3 #include <iostream>
4 #include <vector>
5 #include <string>
6 #include<cstring>
7
8 using std::cin;
9 using std::cout;
10 using std::endl;
11 using std::vector;
12 using std::string;
13
14 class User{
15 public:
16 User(string s1,string s2="123456",string s3="");
17 void set_email();
18 void change_password();
19 void display() const;
20 private:
21 string name;
22 string password;
23 string email;
24 };
25
26 User::User(string s1,string s2,string s3):name{s1},password{s2},email{s3}{};
27 void User::set_email(){
28 int n;
29 string temp;
30 cout<<"Enter email address:";
31 cin>>temp;
32 while((n=temp.find('@'))!=string::npos){
33 cout<<"illegal email.Please re-enter email:";
34 cin>>temp;
35 cout<<endl;
36 }
37 email=temp;
38 cout<<endl;
39 cout<<"email is set successfully..."<<endl;
40 }
41 void User::change_password(){
42 string old,newpass;
43 cout<<"Enter old password:";
44 cin>>old;
45 cout<<endl;
46 for(int i=1;i<3;i++){
47 if(old==password){
48 cout<<"Enter new password:";
49 cin>>newpass;
50 cout<<endl;
51 password=newpass;
52 cout<<"new password is set successfully..."<<endl;
53 return;
54 }
55 else{
56 cout<<"password input error.Please re-enter again:";
57 cin>>old;
58 cout<<endl;
59 }
60 }
61 cout<<"password input error.Please try after a while."<<endl;
62 }
63 void User::display() const{
64 cout<<"name: "<<name<<endl;
65 cout<<"pass: "<<string(password.size(),'*')<<endl;
66 cout<<"email: "<<email<<endl;
67 }
68
69 #include "user.hpp"
70 #include <iostream>
71 #include <vector>
72 #include <string>
73
74 using std::cin;
75 using std::cout;
76 using std::endl;
77 using std::vector;
78 using std::string;
79
80 void test() {
81 vector<User> user_lst;
82
83 User u1("Alice", "2024113", "[email protected]");
84 user_lst.push_back(u1);
85 cout << endl;
86
87 User u2("Bob");
88 u2.set_email();
89 u2.change_password();
90 user_lst.push_back(u2);
91 cout << endl;
92
93 User u3("Hellen");
94 u3.set_email();
95 u3.change_password();
96 user_lst.push_back(u3);
97 cout << endl;
98
99 cout << "There are " << user_lst.size() << " users. they are: " << endl;
100 for(auto &i: user_lst) {
101 i.display();
102 cout << endl;
103 }
104 }
105
106 int main() {
107 test();
108 }
View Code
（2）运行结果
实验任务六
（1）代码部分
1 //date.h
2 #ifndef __DATE_H__
3 #define __DATE_H__
4 class Date {
5 private:
6 int year;
7 int month;
8 int day;
9 int totalDays;
10 public:
11 Date(int year, int month, int day);
12 int getYear() const { return year; }
13 int getMonth() const { return month; }
14 int getDay() const { return day; }
15 int getMaxDay() const;
16 bool isLeapYear() const {
17 return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
18 }
19 void show() const;
20
21 int distance(const Date& date) const {
22 return totalDays - date.totalDays;
23 }
24 };
25 #endif //__DATE_H__
26
27 //date.cpp
28 #include "date.h"
29 #include <iostream>
30 #include <cstdlib>
31 using namespace std;
32 namespace {
33 const int DAYS_BEFORE_MONTH[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
34 }
35 Date::Date(int year, int month, int day) : year(year), month(month), day(day) {
36 if (day <= 0 || day > getMaxDay()) {
37 cout << "Invalid date: ";
38 show();
39 cout << endl;
40 exit(1);
41 }
42 int years = year - 1;
43 totalDays = years * 365 + years / 4 - years / 100 + years / 400
44 + DAYS_BEFORE_MONTH[month - 1] + day;
45 if (isLeapYear() && month > 2) totalDays++;
46 }
47 int Date::getMaxDay() const {
48 if (isLeapYear() && month == 2)
49 return 29;
50 else
51 return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
52 }
53 void Date::show() const {
54 cout << getYear() << "-" << getMonth() << "-" << getDay();
55 }
56
57 //account.h
58 #ifndef __ACCOUNT_H__
59 #define __ACCOUNT_H__
60 #include "date.h"
61 #include <string>
62 class SavingsAccount {
63 private:
64 std::string id;
65 double balance;
66 double rate;
67 Date lastDate;
68 double accumulation;
69 static double total;
70
71 void record(const Date& date, double amount, const std::string& desc);
72
73 void error(const std::string& msg) const;
74
75 double accumulate(const Date& date) const {
76 return accumulation + balance * date.distance(lastDate);
77 }
78 public:
79
80 SavingsAccount(const Date& date, const std::string& id, double rate);
81 const std::string& getId() const { return id; }
82 double getBalance() const { return balance; }
83 double getRate() const { return rate; }
84 static double getTotal() { return total; }
85
86 void deposit(const Date& date, double amount, const std::string& desc);
87
88 void withdraw(const Date& date, double amount, const std::string& desc);
89
90 void settle(const Date& date);
91
92 void show() const;
93 };
94 #endif //__ACCOUNT_H__
95
96
97 //account.cpp
98 #include "account.h"
99 #include <cmath>
100 #include <iostream>
101 using namespace std;
102 double SavingsAccount::total = 0;
103 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate)
104 : id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
105 date.show();
106 cout << "\t#" << id << " created" << endl;
107 }
108 void SavingsAccount::record(const Date& date, double amount, const string& desc) {
109 accumulation = accumulate(date);
110 lastDate = date;
111 amount = floor(amount * 100 + 0.5) / 100;
112 balance += amount;
113 total += amount;
114 date.show();
115 cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
116 }
117 void SavingsAccount::error(const string& msg) const {
118 cout << "Error(#" << id << "): " << msg << endl;
119 }
120 void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
121 record(date, amount, desc);
122 }
123 void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
124 if (amount > getBalance())
125 error("not enough money");
126 else
127 record(date, -amount, desc);
128 }
129 void SavingsAccount::settle(const Date& date) {
130 double interest = accumulate(date) * rate / date.distance(Date(date.getYear() - 1, 1, 1));
131 if (interest != 0)
132 record(date, interest, "interest");
133 accumulation = 0;
134 }
135 void SavingsAccount::show() const {
136 cout << id << "\tBalance: " << balance;
137 }
138
139 //main.cpp
140 #include "account.h"
141 #include <iostream>
142 using namespace std;
143 int main() {
144 Date date(2008, 11, 1);
145 SavingsAccount accounts[] = {
146 SavingsAccount(date, "03755217", 0.015),
147 SavingsAccount(date, "02342342", 0.015)
148 };
149 const int n = sizeof(accounts) / sizeof(SavingsAccount);
150
151 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");
152 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
153
154 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");
155 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
156
157 cout << endl;
158 for (int i = 0; i < n; i++) {
159 accounts[i].settle(Date(2009, 1, 1));
160 accounts[i].show();
161 cout << endl;
162 }
163 cout << "Total: " << SavingsAccount::getTotal() << endl;
164 return 0;
165 }
View Code
（2）运行结果
标签：std,const,string,int,实验,using,cout From： https://www.cnblogs.com/sunnyllyy/p/18525826