实验任务4：

实验代码：

Vector.hpp:

 1 #pragma once
 2 
 3 #include <iostream>
 4 #include <stdexcept>
 5 
 6 using namespace std;
 7 
 8 template <typename T>
 9 class Vector {
10 public:
11     Vector(int n, int value = 0);
12     Vector(const Vector<T> &v);
13     
14     ~Vector() {
15         delete[] ptr;
16     }
17     
18     int get_size() const {return size; }
19     
20     T& at(int index) const;
21     T& at(int index);
22     
23     T& operator[](int index) const;
24     T& operator[](int index);
25     
26     template<typename T1>
27     friend void output(const Vector<T1> &v);
28 private:
29     int size;
30     T *ptr;
31 };
32 
33 template <typename T>
34 Vector<T>::Vector(int n, int value): size{n} {
35     if(n < 0)
36         throw length_error("Vector constructor: negative size");
37     ptr = new T[size];
38     for(int i = 0; i < size; i++)
39         ptr[i] = value;
40 }
41 
42 template <typename T>
43 Vector<T>::Vector(const Vector<T> &v): size{v.size}, ptr{new int[size]} {
44     for(int i = 0; i < size; i++)
45         ptr[i] = v.ptr[i];
46 }
47 
48 template <typename T>
49 T& Vector<T>::at(int index) const {
50     if(index < 0 || index >= size)
51         throw out_of_range("Vector::at(): index out of this->size");
52     return ptr[index];
53 }
54 
55 template <typename T>
56 T& Vector<T>::at(int index) {
57     return static_cast<const Vector*>(this)->at(index);
58 }
59 
60 template <typename T>
61 T& Vector<T>::operator[](int index) const {
62     if(index < 0 || index >= size)
63         throw out_of_range("Vector::opertor[](): index out of this->size");
64     return ptr[index];
65 }
66 
67 template <typename T>
68 T& Vector<T>::operator[](int index) {
69     return static_cast<const Vector*>(this)->operator[](index);
70 }
71 
72 template <typename T>
73 void output(const Vector<T> &v) {
74     for(int i = 0; i < v.get_size(); i++)
75         cout << v.at(i) << ", ";
76     cout << "\b\b \n";
77 }
View Code

task4.cpp:

 1 #include <iostream>
 2 #include "Vector.hpp"
 3 
 4 void test1() {
 5     using namespace std;
 6 
 7     int n;
 8     cout << "Enter n: ";
 9     cin >> n;
10     
11     Vector<double> x1(n);
12     for(auto i = 0; i < n; ++i)
13         x1.at(i) = i * 0.7;
14 
15     cout << "x1: "; output(x1);
16 
17     Vector<int> x2(n, 42);
18     const Vector<int> x3(x2);
19 
20     cout << "x2: "; output(x2);
21     cout << "x3: "; output(x3);
22 
23     x2.at(0) = 77;
24     x2.at(1) = 777;
25     cout << "x2: "; output(x2);
26     cout << "x3: "; output(x3);
27 }
28 
29 void test2() {
30     using namespace std;
31 
32     int n, index;
33     while(cout << "Enter n and index: ", cin >> n >> index) {
34         try {
35             Vector<int> v(n, n);
36             v.at(index) = -999;
37             cout << "v: "; output(v);
38         }
39         catch (const exception &e) {
40             cout << e.what() << endl;
41         }
42     }
43 }
44 
45 int main() {
46     cout << "测试1: 模板类接口测试\n";
47     test1();
48 
49     cout << "\n测试2: 模板类异常处理测试\n";
50     test2();
51 }
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实验截图：

 

实验任务5：

实验代码：

Celebrity.hpp:

 1 #pragma once
 2 
 3 #include <iostream>
 4 #include <fstream>
 5 #include <iomanip>
 6 #include <string>
 7 #include <vector>
 8 
 9 using namespace std;
10 
11 class Celebrity {
12 public:
13     Celebrity() = default;
14     ~Celebrity() = default;
15     string get_major() const {return major; }
16     int get_score() const {return score; }
17     friend ostream& operator<<(ostream &out, const Celebrity &c);
18     friend istream& operator>>(istream &in, Celebrity &c);
19 private:
20     string no;          
21     string name;        
22     string major;       
23     int score;
24 };
25 
26 ostream& operator<<(ostream &out, const Celebrity &c) {
27     out << setiosflags(ios_base::left);
28     out << setw(15) << c.no
29         << setw(15) << c.name
30         << setw(15) << c.major
31         << setw(5) << c.score;
32     return out;
33 }
34 
35 istream& operator>>(istream &in, Celebrity &c) {
36     in >> c.no >> c.name >> c.major >> c.score;
37     return in;
38 }
39 
40 bool compare(const Celebrity &c1, const Celebrity &c2) {
41     if(c1.get_major() != c2.get_major())
42         return c1.get_major() < c2.get_major();
43     else
44         return c1.get_score() > c2.get_score();
45     return false;
46 }
47 
48 void output(ostream &out, const vector<Celebrity> &v) {
49     for(auto &i: v)
50         out << i << endl;
51 }
52 
53 void save(const string &filename, vector<Celebrity> &v) {
54 
55     ofstream out(filename);
56     if(!out.is_open()) {
57         cout << "fail to open file to write\n";
58         return;
59     }
60 
61     output(out, v);
62     out.close();
63 }
64 
65 void load(const string &filename, vector<Celebrity> &v) {
66 
67     ifstream in(filename);
68     if(!in.is_open()) {
69         cout << "fail to open file to read\n";
70         return;
71     }
72 
73     string title_line;
74     getline(in, title_line);     // 跳过标题行
75 
76     Celebrity t;
77     while(in >> t) 
78         v.push_back(t);
79 
80     in.close();
81 }
View Code

task5.cpp:

 1 #include "Celebrity.hpp"
 2 #include <fstream>
 3 #include <iostream>
 4 #include <string>
 5 #include <vector>
 6 #include <algorithm>
 7 
 8 void test() {
 9     using namespace std;
10 
11     vector<Celebrity> v;
12 
13     load("data5.txt", v);   // 从文件加载选手信息到对象v
14     sort(v.begin(), v.end(), compare);  // 按解题情况排序
15     output(cout, v);    // 输出对象v中信息到屏幕
16     save("ans.txt", v); // 把对象v中选手信息保存到文件
17 }
18 
19 int main() {
20     test();
21 }
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实验截图：