任务1
Complex.hpp
1 #pragma once
2
3 #include <iostream>
4 #include <stdexcept>
5
6 // 声明
7 ////////////////////////////////////////////////////
8 // 复数模板类声明
9 template<typename T>
10 class Complex {
11 public:
12 Complex(T r = 0, T i = 0);
13 Complex(const Complex<T> &c);
14
15 T get_real() const;
16 T get_imag() const;
17
18 // 重载+=为成员函数
19 Complex<T>& operator+=(const Complex<T> &c);
20
21 // 重载<<、>>为友元函数
22 template<typename T1>
23 friend std::ostream& operator<<(std::ostream &out, const Complex<T1> &c);
24
25 template<typename T1>
26 friend std::istream& operator>>(std::istream &in, Complex<T1> &c);
27
28 private:
29 T real, imag;
30 };
31
32 // 普通函数声明
33 // 重载+用于Complex类型
34 template<typename T>
35 Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2);
36
37 // 重载==用于Complex类型
38 template<typename T>
39 bool operator==(const Complex<T> &c1, const Complex<T> &c2);
40
41
42 // 实现
43 ////////////////////////////////////////////////////
44 // 成员函数模板实现
45 template<typename T>
46 Complex<T>::Complex(T r, T i): real{r}, imag{i} {
47 }
48
49 template<typename T>
50 Complex<T>::Complex(const Complex<T> &c): real{c.real}, imag{c.imag} {
51 }
52
53 template<typename T>
54 T Complex<T>::get_real() const {
55 return real;
56 }
57
58 template<typename T>
59 T Complex<T>::get_imag() const {
60 return imag;
61 }
62
63 // 重载+=为成员函数
64 template<typename T>
65 Complex<T>& Complex<T>::operator+=(const Complex<T> &c) {
66 real += c.real;
67 imag += c.imag;
68
69 return *this;
70 }
71
72 ///////////////////////////////////////
73 // 友元函数模板实现
74 template<typename T1>
75 std::ostream& operator<<(std::ostream &out, const Complex<T1> &c) {
76 if(c.imag >= 0)
77 out << c.real << " + " << c.imag << "i";
78 else
79 out << c.real << " - " << -c.imag << "i";
80
81 return out;
82 }
83
84 template<typename T1>
85 std::istream& operator>>(std::istream &in, Complex<T1> &c) {
86 in >> c.real >> c.imag;
87
88 return in;
89 }
90
91 ///////////////////////////////////////
92 // 普通函数模板实现
93 // 重载+用于Complex类型
94 template<typename T>
95 Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2) {
96 return Complex<T>(c1.get_real()+c2.get_real(),
97 c1.get_imag()+c2.get_imag());
98 }
99
100 // 重载==用于Complex类型
101 template<typename T>
102 bool operator==(const Complex<T> &c1, const Complex<T> &c2) {
103 return c1.get_real() == c2.get_real() &&
104 c1.get_imag() && c2.get_imag();
105 }
task1.cpp
1 #include "Complex.hpp"
2 #include <iostream>
3 #include <fstream>
4 #include <stdexcept>
5
6 void test1();
7 void test2();
8
9 int main() {
10 using namespace std;
11
12 cout << "测试1: 复数模板类测试" << endl;
13 test1();
14
15 cout << "\n测试2: 文件I/O测试" << endl;
16 test2();
17 }
18
19 void test1() {
20 using namespace std;
21
22 Complex<double> c1{3.5, 2}, c2;
23 cout << "Enter c2: ";
24 cin >> c2;
25 cout << "c1 = " << c1 << endl;
26 cout << "c2 = " << c2 << endl;
27 cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;
28
29 cout << "c1 + c2 = " << c1 + c2 << endl;
30 c1 += c2;
31 cout << "c1.real = " << c1.get_real() << endl;
32 cout << "c1.imag = " << c1.get_imag() << endl;
33
34 cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;
35 }
36
37 void test2() {
38 using namespace std;
39
40 Complex<int> c1{1, 2}, c2{9, -7};
41 ofstream out("ans.txt");
42 if(!out.is_open()) {
43 cout << "fail to open file ans.txt to write\n";
44 return;
45 }
46
47 out << "c1 = " << c1 << endl;
48 out << "c2 = " << c2 << endl;
49 out << "c1 + c2 = " << c1 + c2 << endl;
50 out << "(c1 == c2) = " << boolalpha << (c1 == c2) << endl;
51
52 out.close();
53 cout << "测试ok!" << endl;
54 }
运行结果截图：
任务2
Contestant.hpp
1 #pragma once
2
3 #include <iostream>
4 #include <iomanip>
5 #include <string>
6
7 using std::string;
8 using std::ostream;
9 using std::istream;
10 using std::setw;
11 using std::setprecision;
12 using std::setiosflags;
13 using std::ios_base;
14
15 // Contestant类声明
16 class Contestant {
17 public:
18 Contestant() = default;
19 ~Contestant() = default;
20
21 int get_num() const { return num; }
22 float get_time_usage() const { return time_usage; }
23
24 friend ostream& operator<<(ostream &out, const Contestant &c);
25 friend istream& operator>>(istream &in, Contestant &c);
26
27 private:
28 string no; // 学号
29 string name; // 姓名
30 string major; // 专业
31 int num; // 解题数
32 float time_usage; // 总用时
33 };
34
35 // 友元函数实现
36 // 重载流插入运算符<<
37 ostream& operator<<(ostream &out, const Contestant &c) {
38 out << setiosflags(ios_base::left);
39 out << setw(15) << c.no
40 << setw(15) << c.name
41 << setw(15) << c.major
42 << setw(5) << c.num
43 << setprecision(2) << c.time_usage;
44
45 return out;
46 }
47
48 // 重载流提取运算符>>
49 istream& operator>>(istream &in, Contestant &c) {
50 in >> c.no >> c.name >> c.major >> c.num >> c.time_usage;
51
52 return in;
53 }
utils.hpp
1 #include "Contestant.hpp"
2 #include <fstream>
3 #include <iostream>
4 #include <string>
5 #include <vector>
6
7 // 排序函数
8 // 按解题数比较，解题数相同的情况下，按总用时比较，总用时越少，排名越靠前
9 bool compare_by_solutionInfo(const Contestant &c1, const Contestant &c2) {
10 if(c1.get_num() > c2.get_num())
11 return true;
12
13 if(c1.get_num() == c2.get_num())
14 return c1.get_time_usage() < c2.get_time_usage();
15
16 return false;
17 }
18
19 // 把vector<Constestant>对象中的元素插入到输出流out
20 void output(std::ostream &out, const std::vector<Contestant> &v) {
21 for(auto &i: v)
22 out << i << std::endl;
23 }
24
25
26 // 把vector<Contestant>对象中的元素写到filename文件中
27 void save(const std::string &filename, std::vector<Contestant> &v) {
28 using std::ofstream;
29
30 ofstream out(filename);
31 if(!out.is_open()) {
32 std::cout << "fail to open file to write\n";
33 return;
34 }
35
36 output(out, v);
37 out.close();
38 }
39
40 // 从文件filename读取参赛选手信息到vector<Contestant>对象
41 void load(const std::string &filename, std::vector<Contestant> &v) {
42 using std::ifstream;
43
44 ifstream in(filename);
45 if(!in.is_open()) {
46 std::cout << "fail to open file to read\n";
47 return;
48 }
49
50 std::string title_line;
51 getline(in, title_line); // 跳过标题行
52
53 int first_column;
54 Contestant t;
55 while(in >> first_column >> t)
56 v.push_back(t);
57
58 in.close();
59 }
task2.cpp
1 #include "Contestant.hpp"
2 #include "utils.hpp"
3 #include <iostream>
4 #include <vector>
5 #include <algorithm>
6
7
8 void test() {
9 using namespace std;
10
11 vector<Contestant> v;
12
13 load("data2.txt", v); // 从文件加载选手信息到对象v
14 sort(v.begin(), v.end(), compare_by_solutionInfo); // 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 }
运行结果截图：
任务3
Triangle.hpp
1 #include <iostream>
2 #include <stdexcept>
3 #include <cmath>
4
5 using namespace std;
6
7 class Triangle {
8 public:
9 Triangle(double s1, double s2, double s3);
10 ~Triangle() = default;
11
12 double area() const;
13
14 private:
15 double a, b, c;
16 };
17
18 Triangle::Triangle(double s1, double s2, double s3): a{s1}, b{s2}, c{s3} {
19 if(a <= 0 || b <= 0 || c <= 0)
20 throw invalid_argument("边长出现负值");
21
22 if(a+b <= c || b+c <= a || a+c <= b)
23 throw invalid_argument("不满足任意两边之和大于第三边");
24 }
25
26 double Triangle::area() const {
27 double s = (a + b + c)/2;
28 return sqrt(s*(s-a)*(s-b)*(s-c));
29 }
task3.cpp
1 #include "Triangle.hpp"
2 #include <iostream>
3 #include <fstream>
4
5 void test() {
6 using namespace std;
7
8 cout << "从文件读入三角形三边边长，计算面积" << endl;
9
10 ifstream in("data3.txt");
11 if(!in.is_open()) {
12 cout << "fail to open file to read\n";
13 return;
14 }
15
16 double a,b,c;
17 do {
18 cout << "三角形边长: ";
19 in >> a >> b >> c;
20 cout << a << " " << b << " " << c << endl;
21
22 try {
23 Triangle t(a, b, c);
24 cout << "三角形面积: " << t.area() << endl << endl;
25 }catch(const exception &e) {
26 cout << "error: " << e.what() << endl << endl;
27 }
28
29 if(in.peek() == EOF)
30 break;
31 } while(1);
32
33 in.close();
34 }
35
36 int main() {
37 test();
38 }
运行结果截图：
任务4
Vector.hpp
1 #ifndef VECTOR_HPP
2 #define VECTOR_HPP
3
4 #include <iostream>
5 #include <stdexcept>
6
7 template <typename T>
8 class Vector {
9 private:
10 T* data;
11 int size;
12
13 public:
14 Vector(int n, const T& value = T()) {
15 if (n < 0) throw std::length_error("Vector constructor: negative size");
16 size = n;
17 data = new T[size];
18 for (int i = 0; i < size; ++i) {
19 data[i] = value;
20 }
21 }
22 Vector(const Vector<T>& other) {
23 size = other.size;
24 data = new T[size];
25 for (int i = 0; i < size; ++i) {
26 data[i] = other.data[i];
27 }
28 }
29 ~Vector() {
30 delete[] data;
31 }
32 int get_size() const {
33 return size;
34 }
35 T& at(int index) {
36 if (index < 0 || index >= size) throw std::out_of_range("Vector: index out of range");
37 return data[index];
38 }
39
40 const T& at(int index) const {
41 if (index < 0 || index >= size) throw std::out_of_range("Vector: index out of range");
42 return data[index];
43 }
44 T& operator[](int index) {
45 if (index < 0 || index >= size) throw std::out_of_range("Vector: index out of range");
46 return data[index];
47 }
48
49 const T& operator[](int index) const {
50 if (index < 0 || index >= size) throw std::out_of_range("Vector: index out of range");
51 return data[index];
52 }
53 template <typename U>
54 friend void output(const Vector<U>& v);
55 };
56 template <typename T>
57 void output(const Vector<T>& v) {
58 for (int i = 0; i < v.size; ++i) {
59 std::cout << v.data[i] << " ";
60 }
61 std::cout << std::endl;
62 }
63
64 #endif // VECTOR_HPP
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 }
运行结果截图：
任务5
task5.cpp
1 #include <iostream>
2 #include <fstream>
3 #include <vector>
4 #include <string>
5 #include <algorithm>
6
7 using namespace std;
8 struct Student {
9 string id; // 学号
10 string name; // 姓名
11 string major; // 专业
12 int score; // 分数
13 };
14
15 bool readData(const string& filename, vector<Student>& students) {
16 ifstream infile(filename);
17 if (!infile) {
18 cerr << "Error: Cannot open file " << filename << endl;
19 return false;
20 }
21 string header;
22 getline(infile, header);
23
24 Student temp;
25 while (infile >> temp.id >> temp.name >> temp.major >> temp.score) {
26 students.push_back(temp);
27 }
28
29 infile.close();
30 return true;
31 }
32
33 void writeData(const string& filename, const vector<Student>& students) {
34 ofstream outfile(filename);
35 if (!outfile) {
36 cerr << "Error: Cannot open file " << filename << endl;
37 return;
38 }
39
40 outfile << "学号\t姓名\t专业\t分数\n";
41 for (const auto& s : students) {
42 outfile << s.id << "\t" << s.name << "\t" << s.major << "\t" << s.score << "\n";
43 }
44
45 outfile.close();
46 }
47 bool compareStudents(const Student& a, const Student& b) {
48 if (a.major != b.major) return a.major < b.major;
49 return a.score > b.score;
50 }
51
52 void printStudents(const vector<Student>& students) {
53 cout << "学号\t姓名\t专业\t分数\n";
54 for (const auto& s : students) {
55 cout << s.id << "\t" << s.name << "\t" << s.major << "\t" << s.score << endl;
56 }
57 }
58
59 int main() {
60 vector<Student> students;
61
62 if (!readData("data5.txt", students)) {
63 return 1;
64 }
65
66 sort(students.begin(), students.end(), compareStudents);
67
68 cout << "排序后的学生信息:\n";
69 printStudents(students);
70
71 writeData("ans5.txt", students);
72 cout << "\n排序结果已保存到文件 ans5.txt" << endl;
73
74 return 0;
75 }
运行结果截图：
标签：std,文件,const,index,get,Complex,实验,include,模板 From： https://www.cnblogs.com/rxt711/p/18610700