#pragma once#include <iostream> #include <stdexcept>// 声明 //////////////////////////////////////////////////// // 复数模板类声明 template<typename T> class Complex { public:Complex(T r = 0, T i = 0);Complex(const Complex<T> &c);T get_real() const;T get_imag() const;// 重载+=为成员函数Complex<T>& operator+=(const Complex<T> &c);// 重载<<、>>为友元函数template<typename T1>friend std::ostream& operator<<(std::ostream &out, const Complex<T1> &c);template<typename T1>friend std::istream& operator>>(std::istream &in, Complex<T1> &c);private:T real, imag; };// 普通函数声明 // 重载+用于Complex类型 template<typename T> Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2);// 重载==用于Complex类型 template<typename T> bool operator==(const Complex<T> &c1, const Complex<T> &c2);// 实现 //////////////////////////////////////////////////// // 成员函数模板实现 template<typename T> Complex<T>::Complex(T r, T i): real{r}, imag{i} { }template<typename T> Complex<T>::Complex(const Complex<T> &c): real{c.real}, imag{c.imag} { }template<typename T> T Complex<T>::get_real() const {return real; }template<typename T> T Complex<T>::get_imag() const {return imag; }// 重载+=为成员函数 template<typename T> Complex<T>& Complex<T>::operator+=(const Complex<T> &c) {real += c.real;imag += c.imag;return *this; }/////////////////////////////////////// // 友元函数模板实现 template<typename T1> std::ostream& operator<<(std::ostream &out, const Complex<T1> &c) {if(c.imag >= 0)out << c.real << " + " << c.imag << "i";elseout << c.real << " - " << -c.imag << "i";return out; }template<typename T1> std::istream& operator>>(std::istream &in, Complex<T1> &c) {in >> c.real >> c.imag;return in; }/////////////////////////////////////// // 普通函数模板实现 // 重载+用于Complex类型 template<typename T> Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2) {return Complex<T>(c1.get_real()+c2.get_real(), c1.get_imag()+c2.get_imag()); }// 重载==用于Complex类型 template<typename T> bool operator==(const Complex<T> &c1, const Complex<T> &c2) {return c1.get_real() == c2.get_real() && c1.get_imag() && c2.get_imag(); }#include "Complex.hpp" #include <iostream> #include <fstream> #include <stdexcept>void test1(); void test2();int main() {using namespace std;cout << "测试1: 复数模板类测试" << endl;test1();cout << "\n测试2: 文件I/O测试" << endl;test2(); }void test1() {using namespace std;Complex<double> c1{3.5, 2}, c2;cout << "Enter c2: ";cin >> c2;cout << "c1 = " << c1 << endl;cout << "c2 = " << c2 << endl;cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;cout << "c1 + c2 = " << c1 + c2 << endl;c1 += c2;cout << "c1.real = " << c1.get_real() << endl;cout << "c1.imag = " << c1.get_imag() << endl;cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl; }void test2() {using namespace std;Complex<int> c1{1, 2}, c2{9, -7};ofstream out("ans.txt");if(!out.is_open()) {cout << "fail to open file ans.txt to write\n";return;}out << "c1 = " << c1 << endl;out << "c2 = " << c2 << endl;out << "c1 + c2 = " << c1 + c2 << endl;out << "(c1 == c2) = " << boolalpha << (c1 == c2) << endl;out.close();cout << "测试ok!" << endl; }
实验任务二：
#pragma once#include <iostream> #include <iomanip> #include <string>using std::string; using std::ostream; using std::istream; using std::setw; using std::setprecision; using std::setiosflags; using std::ios_base;// Contestant类声明 class Contestant { public:Contestant() = default;~Contestant() = default;int get_num() const { return num; }float get_time_usage() const { return time_usage; }friend ostream& operator<<(ostream &out, const Contestant &c);friend istream& operator>>(istream &in, Contestant &c);private:string no; // 学号string name; // 姓名string major; // 专业int num; // 解题数float time_usage; // 总用时 };// 友元函数实现 // 重载流插入运算符<< ostream& operator<<(ostream &out, const Contestant &c) {out << setiosflags(ios_base::left);out << setw(15) << c.no<< setw(15) << c.name<< setw(15) << c.major<< setw(5) << c.num<< setprecision(2) << c.time_usage;return out; }// 重载流提取运算符>> istream& operator>>(istream &in, Contestant &c) {in >> c.no >> c.name >> c.major >> c.num >> c.time_usage;return in; }#include "Contestant.hpp" #include "utils.hpp" #include <iostream> #include <vector> #include <algorithm>void test() {using namespace std;vector<Contestant> v;load("data2.txt", v); // 从文件加载选手信息到对象vsort(v.begin(), v.end(), compare_by_solutionInfo); // 按解题情况排序output(cout, v); // 输出对象v中信息到屏幕save("ans.txt", v); // 把对象v中选手信息保存到文件 }int main() {test(); }#include "Contestant.hpp" #include <fstream> #include <iostream> #include <string> #include <vector>// 排序函数 // 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 bool compare_by_solutionInfo(const Contestant &c1, const Contestant &c2) {if(c1.get_num() > c2.get_num())return true;if(c1.get_num() == c2.get_num())return c1.get_time_usage() < c2.get_time_usage();return false; }// 把vector<Constestant>对象中的元素插入到输出流out void output(std::ostream &out, const std::vector<Contestant> &v) {for(auto &i: v)out << i << std::endl; }// 把vector<Contestant>对象中的元素写到filename文件中 void save(const std::string &filename, std::vector<Contestant> &v) {using std::ofstream;ofstream out(filename);if(!out.is_open()) {std::cout << "fail to open file to write\n";return;}output(out, v);out.close(); }// 从文件filename读取参赛选手信息到vector<Contestant>对象 void load(const std::string &filename, std::vector<Contestant> &v) {using std::ifstream;ifstream in(filename);if(!in.is_open()) {std::cout << "fail to open file to read\n";return;}std::string title_line;getline(in, title_line); // 跳过标题行int first_column;Contestant t;while(in >> first_column >> t) v.push_back(t);in.close(); }
实验任务三：
#include <iostream> #include <stdexcept> #include <cmath>using namespace std;class Triangle { public:Triangle(double s1, double s2, double s3);~Triangle() = default;double area() const;private:double a, b, c; };Triangle::Triangle(double s1, double s2, double s3): a{s1}, b{s2}, c{s3} {if(a <= 0 || b <= 0 || c <= 0)throw invalid_argument("边长出现负值");if(a+b <= c || b+c <= a || a+c <= b) throw invalid_argument("不满足任意两边之和大于第三边"); }double Triangle::area() const {double s = (a + b + c)/2;return sqrt(s*(s-a)*(s-b)*(s-c)); }#include "Triangle.hpp" #include <iostream> #include <fstream>void test() {using namespace std;cout << "从文件读入三角形三边边长，计算面积" << endl;ifstream in("data3.txt");if(!in.is_open()) {cout << "fail to open file to read\n";return;}double a,b,c;do {cout << "三角形边长: ";in >> a >> b >> c;cout << a << " " << b << " " << c << endl;try {Triangle t(a, b, c);cout << "三角形面积: " << t.area() << endl << endl;}catch(const exception &e) {cout << "error: " << e.what() << endl << endl;}if(in.peek() == EOF)break;} while(1);in.close(); }int main() {test(); }
实验任务四：
#include<iostream> using namespace std; #include<vector> template<typename T> class Vector { public:Vector(int n) {if (n < 0) throw length_error("数组大小不能为负数");arr_length = n;arr = new T[n];}Vector() : arr(nullptr), arr_length(0) {}Vector(int n, T init) {if (n < 0)throw length_error("数组大小不能为负数");arr_length = n;arr = new T[n];if (init < 0)throw length_error("数组元素不能为负数");for (int i = 0; i < n; ++i) {arr[i] = init;}}Vector(const Vector<T>& a) {arr_length = a.arr_length;arr = new T[a.arr_length];for (int i = 0; i < a.arr_length; ++i) {arr[i] = a.arr[i];}}~Vector() {delete []arr;}int get_size() {return arr_length;}T& at(int n) {if (n < 0 || n >= arr_length)throw out_of_range("下标越界");return arr[n];}T& operator[](int n) {if (n < 0 || n >= arr_length)throw out_of_range("下标越界");return arr[n];}template<typename T1>friend void output(const Vector<T1> &a) ; private:T* arr;int arr_length; }; template<typename T1> void output(const Vector<T1>& a) {for (int i = 0; i < a.arr_length; ++i)cout << a.arr[i]<<" ";cout << endl; }
#include <iostream> #include "C:\Users\29114\source\repos\MAJORCPP\Vector.hpp"void test1() {using namespace std;int n;cout << "Enter n: ";cin >> n;Vector<double> x1(n);for(auto i = 0; i < n; ++i)x1.at(i) = i * 0.7;cout << "x1: "; output(x1);Vector<int> x2(n, 42);const Vector<int> x3(x2);cout << "x2: "; output(x2);cout << "x3: "; output(x3);x2.at(0) = 77;x2.at(1) = 777;cout << "x2: "; output(x2);cout << "x3: "; output(x3); }void test2() {using namespace std;int n, index;while(cout << "Enter n and index: ", cin >> n >> index) {try {Vector<int> v(n, n);v.at(index) = -999;cout << "v: "; output(v);}catch (const exception &e) {cout << e.what() << endl;}} }int main() {cout << "测试1: 模板类接口测试\n";test1();cout << "\n测试2: 模板类异常处理测试\n";test2(); }
实验任务五：
#include<iostream> using namespace std;#include<string> #include<iomanip> class stu { public:string num;string name;string major;string score; public ://顺序stu(string a, string b, string c, string d) :num{ a }, name{ b }, major{ c }, score{ d } {}void display() {cout << left << setw(18) << num;cout << left << setw(18) << name;cout << left << setw(18) << major;cout << left << setw(18) << score<<endl;} };
#include<iostream> using namespace std; #include"task5sef.hpp" #include<vector> #include <algorithm> #include<fstream> #include <sstream> bool compare(const stu &s1, const stu &s2) {if (!(s1.major == s2.major))return s1.major < s2.major;else{ return s1.score >s2.score;} } int main() {ifstream in("data5.txt");vector<stu> arr;if (in.is_open()){string line;getline(in, line);while (getline(in, line)) {stringstream ss(line);string num;string name;string major;string score;ss >> num >> name >> major >> score;arr.push_back(stu(num, name, major, score));}in.close();}elsecerr << "无法打开文件" << endl;sort(arr.begin(), arr.end(), compare);for (auto i : arr) {i.display();}ofstream out("data5_1.txt");if (out.is_open()) {for (auto i : arr) {out << i.num << " " << i.name << " " << i.major << " " << i.score<<endl;}out.close();}elsecerr << "无法写入文件" << endl;}
