实验6
task1
task1.cpp
#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;
}
complex.hpp
#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";
else
out << 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();
}
task2
task2.cpp
#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v
sort(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();
}
Contestant.hpp
#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v
sort(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();
}
utils.hpp
#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();
}
task3
task3.cpp
#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();
}
Triangle.hpp
#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));
}
task4
task4.cpp
#include <iostream>
#include "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();
}
Vector.hpp
#pragma once
#include<iostream>
#include<stdexcept>
#include<cmath>
using namespace std;
template<typename T>
class Vector {
public:
Vector(int s ) :size{ s } {
if (s < 0)
throw std::length_error("vector constructor:negative size");
ptr = new T[size];
}
Vector(int s , T value ) :size{ s } {
if (s < 0)
throw std::length_error("vector constructor:negative size");
ptr = new T[size];
for (int i = 0; i < size; ++i)
ptr[i] = value;
}
Vector(const Vector<T>& v) :size{ v.size }, ptr{ new T[size] } {
for (int i = 0; i < size; ++i)
ptr[i] = v.ptr[i];
}
~Vector() { delete[]ptr; }
int get_size() { return size; }
T& at(int index)const {
if (index < 0 || index >= size)
throw std::out_of_range("vector::at():index out of this->size");
return ptr[index];
}
T& operator[](int index) {
if (index < 0 || index >= size)
throw std::out_of_range("vector::operator[]():index out of this->size");
return ptr[index];
}
friend void output(const Vector<T>v) {
for (int i = 0; i < v.size; i++)
cout << v.at(i) << ",";
cout << "\b\b\n";
}
private:
int size;
T* ptr;
};
task5
task5.cpp
#include<iostream>
#include<fstream>
#include<string>
#include<vector>
#include<iomanip>
#include<algorithm>
using namespace std;
class student{
public:
student() = default;
~student() = default;
string get_major()const {
return major;
}
int get_score()const {
return score;
}
friend ostream& operator<<(ostream& out, const student& s) {
out << setiosflags(ios_base::left);
out << setw(10) << s.number
<< setw(10) << s.name
<< setw(10) << s.major
<< setw(10) << s.score;
return out;
}
friend istream& operator>>(istream& in, student& s) {
in >>s.number >> s.name >> s.major >> s.score;
return in;
}
private:
string number;
string name;
string major;
int score;
};
bool compare(const student& s1, const student& s2) {
if (s1.get_major() < s2.get_major())
return true;
if (s1.get_major() == s2.get_major())
return s1.get_score() > s2.get_score();
return false;
}
void output(ostream& out, const vector<student>& v) {
for (auto& i : v)
out << i << endl;
}
void save(const string& filename, vector<student>& v) {
ofstream out(filename);
if (!out.is_open()) {
cout << "fail to open file to write\n";
return;
}
output(out, v);
out.close();
}
void load(const string& filename, vector<student>& v) {
ifstream in(filename);
if (!in.is_open()) {
cout << "fail to open to read\n";
return;
}
string title_line;
getline(in, title_line);
student t;
while (in >> t)
v.push_back(t);
in.close();
}
int main() {
vector<student>v;
load("data5.txt", v);
sort(v.begin(), v.end(), compare);
output(cout, v);
save("ans5.txt", v);
}
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