task1:
1 //Complex.hpp
2 #pragma once
3
4 #include <iostream>
5 #include <stdexcept>
6
7 // 声明
8 ////////////////////////////////////////////////////
9 // 复数模板类声明
10 template<typename T>
11 class Complex {
12 public:
13 Complex(T r = 0, T i = 0);
14 Complex(const Complex<T> &c);
15
16 T get_real() const;
17 T get_imag() const;
18
19 // 重载+=为成员函数
20 Complex<T>& operator+=(const Complex<T> &c);
21
22 // 重载<<、>>为友元函数
23 template<typename T1>
24 friend std::ostream& operator<<(std::ostream &out, const Complex<T1> &c);
25
26 template<typename T1>
27 friend std::istream& operator>>(std::istream &in, Complex<T1> &c);
28
29 private:
30 T real, imag;
31 };
32
33 // 普通函数声明
34 // 重载+用于Complex类型
35 template<typename T>
36 Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2);
37
38 // 重载==用于Complex类型
39 template<typename T>
40 bool operator==(const Complex<T> &c1, const Complex<T> &c2);
41
42
43 // 实现
44 ////////////////////////////////////////////////////
45 // 成员函数模板实现
46 template<typename T>
47 Complex<T>::Complex(T r, T i): real{r}, imag{i} {
48 }
49
50 template<typename T>
51 Complex<T>::Complex(const Complex<T> &c): real{c.real}, imag{c.imag} {
52 }
53
54 template<typename T>
55 T Complex<T>::get_real() const {
56 return real;
57 }
58
59 template<typename T>
60 T Complex<T>::get_imag() const {
61 return imag;
62 }
63
64 // 重载+=为成员函数
65 template<typename T>
66 Complex<T>& Complex<T>::operator+=(const Complex<T> &c) {
67 real += c.real;
68 imag += c.imag;
69
70 return *this;
71 }
72
73 ///////////////////////////////////////
74 // 友元函数模板实现
75 template<typename T1>
76 std::ostream& operator<<(std::ostream &out, const Complex<T1> &c) {
77 if(c.imag >= 0)
78 out << c.real << " + " << c.imag << "i";
79 else
80 out << c.real << " - " << -c.imag << "i";
81
82 return out;
83 }
84
85 template<typename T1>
86 std::istream& operator>>(std::istream &in, Complex<T1> &c) {
87 in >> c.real >> c.imag;
88
89 return in;
90 }
91
92 ///////////////////////////////////////
93 // 普通函数模板实现
94 // 重载+用于Complex类型
95 template<typename T>
96 Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2) {
97 return Complex<T>(c1.get_real()+c2.get_real(),
98 c1.get_imag()+c2.get_imag());
99 }
100
101 // 重载==用于Complex类型
102 template<typename T>
103 bool operator==(const Complex<T> &c1, const Complex<T> &c2) {
104 return c1.get_real() == c2.get_real() &&
105 c1.get_imag() && c2.get_imag();
106 }
View Code
1 //task1.cpp
2 #include "Complex.hpp"
3 #include <iostream>
4 #include <fstream>
5 #include <stdexcept>
6
7 void test1();
8 void test2();
9
10 int main() {
11 using namespace std;
12
13 cout << "测试1: 复数模板类测试" << endl;
14 test1();
15
16 cout << "\n测试2: 文件I/O测试" << endl;
17 test2();
18 }
19
20 void test1() {
21 using namespace std;
22
23 Complex<double> c1{3.5, 2}, c2;
24 cout << "Enter c2: ";
25 cin >> c2;
26 cout << "c1 = " << c1 << endl;
27 cout << "c2 = " << c2 << endl;
28 cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;
29
30 cout << "c1 + c2 = " << c1 + c2 << endl;
31 c1 += c2;
32 cout << "c1.real = " << c1.get_real() << endl;
33 cout << "c1.imag = " << c1.get_imag() << endl;
34
35 cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;
36 }
37
38 void test2() {
39 using namespace std;
40
41 Complex<int> c1{1, 2}, c2{9, -7};
42 ofstream out("ans.txt");
43 if(!out.is_open()) {
44 cout << "fail to open file ans.txt to write\n";
45 return;
46 }
47
48 out << "c1 = " << c1 << endl;
49 out << "c2 = " << c2 << endl;
50 out << "c1 + c2 = " << c1 + c2 << endl;
51 out << "(c1 == c2) = " << boolalpha << (c1 == c2) << endl;
52
53 out.close();
54 cout << "测试ok!" << endl;
55 }
View Code
代码：
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task 2:
代码：
1 //Contestent.hpp
2 #pragma once
3
4 #include <iostream>
5 #include <iomanip>
6 #include <string>
7
8 using std::string;
9 using std::ostream;
10 using std::istream;
11 using std::setw;
12 using std::setprecision;
13 using std::setiosflags;
14 using std::ios_base;
15
16 // Contestant类声明
17 class Contestant {
18 public:
19 Contestant() = default;
20 ~Contestant() = default;
21
22 int get_num() const { return num; }
23 float get_time_usage() const { return time_usage; }
24
25 friend ostream& operator<<(ostream &out, const Contestant &c);
26 friend istream& operator>>(istream &in, Contestant &c);
27
28 private:
29 string no; // 学号
30 string name; // 姓名
31 string major; // 专业
32 int num; // 解题数
33 float time_usage; // 总用时
34 };
35
36 // 友元函数实现
37 // 重载流插入运算符<<
38 ostream& operator<<(ostream &out, const Contestant &c) {
39 out << setiosflags(ios_base::left);
40 out << setw(15) << c.no
41 << setw(15) << c.name
42 << setw(15) << c.major
43 << setw(5) << c.num
44 << setprecision(2) << c.time_usage;
45
46 return out;
47 }
48
49 // 重载流提取运算符>>
50 istream& operator>>(istream &in, Contestant &c) {
51 in >> c.no >> c.name >> c.major >> c.num >> c.time_usage;
52
53 return in;
54 }
View Code
1 //utils.hpp
2 #include "Contestant.hpp"
3 #include <fstream>
4 #include <iostream>
5 #include <string>
6 #include <vector>
7
8 // 排序函数
9 // 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
10 bool compare_by_solutionInfo(const Contestant &c1, const Contestant &c2) {
11 if(c1.get_num() > c2.get_num())
12 return true;
13
14 if(c1.get_num() == c2.get_num())
15 return c1.get_time_usage() < c2.get_time_usage();
16
17 return false;
18 }
19
20 // 把vector<Constestant>对象中的元素插入到输出流out
21 void output(std::ostream &out, const std::vector<Contestant> &v) {
22 for(auto &i: v)
23 out << i << std::endl;
24 }
25
26
27 // 把vector<Contestant>对象中的元素写到filename文件中
28 void save(const std::string &filename, std::vector<Contestant> &v) {
29 using std::ofstream;
30
31 ofstream out(filename);
32 if(!out.is_open()) {
33 std::cout << "fail to open file to write\n";
34 return;
35 }
36
37 output(out, v);
38 out.close();
39 }
40
41 // 从文件filename读取参赛选手信息到vector<Contestant>对象
42 void load(const std::string &filename, std::vector<Contestant> &v) {
43 using std::ifstream;
44
45 ifstream in(filename);
46 if(!in.is_open()) {
47 std::cout << "fail to open file to read\n";
48 return;
49 }
50
51 std::string title_line;
52 getline(in, title_line); // 跳过标题行
53
54 int first_column;
55 Contestant t;
56 while(in >> first_column >> t)
57 v.push_back(t);
58
59 in.close();
60 }
View Code
//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();
}
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task3:
代码：
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 }
View Code
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 }
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task4:
代码：
1 //task4.cpp
2 #include <iostream>
3 #include "Vector.hpp"
4
5 void test1() {
6 using namespace std;
7
8 int n;
9 cout << "Enter n: ";
10 cin >> n;
11
12 Vector<double> x1(n);
13 for(auto i = 0; i < n; ++i)
14 x1.at(i) = i * 0.7;
15
16 cout << "x1: "; output(x1);
17
18 Vector<int> x2(n, 42);
19 const Vector<int> x3(x2);
20
21 cout << "x2: "; output(x2);
22 cout << "x3: "; output(x3);
23
24 x2.at(0) = 77;
25 x2.at(1) = 777;
26 cout << "x2: "; output(x2);
27 cout << "x3: "; output(x3);
28 }
29
30 void test2() {
31 using namespace std;
32
33 int n, index;
34 while(cout << "Enter n and index: ", cin >> n >> index) {
35 try {
36 Vector<int> v(n, n);
37 v.at(index) = -999;
38 cout << "v: "; output(v);
39 }
40 catch (const exception &e) {
41 cout << e.what() << endl;
42 }
43 }
44 }
45
46 int main() {
47 cout << "测试1: 模板类接口测试\n";
48 test1();
49
50 cout << "\n测试2: 模板类异常处理测试\n";
51 test2();
52 }
View Code
//vector.hpp
#include<iostream>
#include<stdexcept>
using namespace std;
template<typename T>
class Vector{
private:
int size;
T *ptr;
public:
Vector(int s):size(s){
if(s<0)
throw length_error("Vector constructor:negative size");
else
ptr=new T[size];
}
Vector(int s,T value):size(s){
if(s<0)
throw length_error("Vector constructor:negative size");
else
{
ptr=new T[size];
for(int i=0;i<s;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();
T& at(int index);
T& operator[](int index);
friend void output(Vector<T> v){
for(int i=0;i<v.size;i++)
cout<<v.ptr[i]<<"，";
cout<<endl;
}
};
template<typename T>
int Vector<T>::get_size(){return size;}
template<typename T>
T& Vector<T>::at(int index){
if (index<0||index>=size)
throw out_of_range("Vector:index out of range");
return *(ptr+index);
}
template<typename T>
T& Vector<T>::operator[](int index){
if (index<0||index>=size)
throw out_of_range("Vector:index out of range");
return *(ptr+index);
}
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task5:
代码：
1 #include"student.hpp"
2 #include<vector>
3 #include <fstream>
4 #include <iostream>
5 #include<string>
6 #include <algorithm>
7 using namespace std;
8
9 void output(ostream &out,vector<student>& v) {
10 for(auto& i:v)
11 out<<i<<endl;
12 }
13
14
15 void save(const string &filename,vector<student> &v) {
16 using std::ofstream;
17
18 ofstream out(filename);
19 if(!out.is_open()) {
20 std::cout << "fail to open file to write\n";
21 exit(0);
22 }
23
24 output(out, v);
25 out.close();
26 }
27
28 bool compare_by_score(student &s1,student &s2) {
29 if(s1.get_score() > s2.get_score())
30 return true;
31
32 if(s1.get_score() == s2.get_score())
33 return s1.get_major() < s2.get_major();
34
35 return false;
36 }
37
38 void load(const string &filename,vector<student> &v) {
39 using std::ifstream;
40
41 ifstream in(filename);
42 if(!in.is_open()) {
43 std::cout << "fail to open file to read\n";
44 exit(0);
45 }
46
47 std::string title_line;
48 getline(in, title_line);
49
50 student t;
51 while(in >> t)
52 v.push_back(t);
53
54 in.close();
55 }
56
57 int main(){
58 vector<student> v;
59 load("data5.txt", v);
60 sort(v.begin(), v.end(), compare_by_score);
61 output(cout, v);
62 save("ans5.txt", v);
63 return 0;
64 }
View Code
1 #pragma once
2 #include <iomanip>
3 #include <iostream>
4 #include<string>
5 #include<fstream>
6 #include<algorithm>
7 using namespace std;
8 class student{
9 private:
10 int number;
11 string name;
12 string major;
13 int score;
14 public:
15 student()=default;
16 ~student()=default;
17 int get_score(){return score;}
18 string get_major(){return major;}
19 friend ostream& operator<<(ostream &out,student &s);
20 friend istream& operator>>(istream &in,student &s);
21 };
22 ostream& operator<<(ostream &out,student &s){
23 out<<left;
24 out<<setw(15)<<s.number<<setw(15)<<s.name<<setw(15)<<s.major<<setw(15)<<s.score;
25 return out;
26 }
27 istream& operator>>(istream &in,student &s){
28 in>>s.number>>s.name>>s.major>>s.score;
29 return in;
30 }
View Code
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标签：std,文件,const,get,Complex,实验,return,include,模板 From： https://www.cnblogs.com/nofear77/p/18621406