task4
Vector.hpp
1 #pragma once
2
3 #include <iostream>
4 #include <stdexcept>
5
6 using std::cout;
7 using std::endl;
8
9 template<typename T>
10 class Vector {
11 public:
12 Vector(int size0 = 0);
13 Vector(int size0, T same_value);
14 Vector(const Vector<T>& v);
15 ~Vector();
16
17 int get_size() const;
18 T& at(int index) const;
19 T& at(int index);
20
21 T& operator[](int index) const;
22 T& operator[](int index);
23
24 template<typename T1>
25 friend void output(const Vector<T1>& v);
26
27 private:
28 int size;
29 T* ptr;
30 };
31
32 template<typename T>
33 Vector<T>::Vector(int size0) : size{ size0 } {
34 if (size < 0)
35 throw std::length_error("vectorInt constructor: negative size");
36
37 ptr = new T[size];
38 }
39
40 template<typename T>
41 Vector<T>::Vector(int size0, T same_value) : size{ size0 } {
42 if (size < 0)
43 throw std::length_error("vectorInt constructor: negative size");
44
45 ptr = new T[size];
46 for (int i = 0; i < size; ++i)
47 ptr[i] = same_value;
48 }
49
50 template<typename T>
51 Vector<T>::Vector(const Vector<T>& v) : size{ v.size }, ptr{ new T[size] } {//? get_size()
52 for (int i = 0; i < size; ++i)
53 ptr[i] = v.ptr[i];
54 }
55
56 template<typename T>
57 Vector<T>::~Vector() {
58 delete[] ptr;
59 }
60
61 template<typename T>
62 int Vector<T>::get_size() const {
63 return size;
64 }
65
66 template<typename T>
67 T& Vector<T>::at(int index) const {
68 if (index < 0 || index >= size)
69 throw std::out_of_range("vectorInt::operator[](): index out of this->size");
70
71 return ptr[index];
72 }
73
74 template<typename T>
75 T& Vector<T>::at(int index) {
76 return static_cast<const Vector<T>*>(this)->at(index);
77 }
78
79 template<typename T>
80 T& Vector<T>::operator[](int index) const {
81 if (index < 0 || index >= size)
82 throw std::out_of_range("vectorInt::operator[](): index out of this-> size");
83
84 return ptr[index];
85 }
86
87 template<typename T>
88 T& Vector<T>::operator[](int index) {
89 return static_cast<const Vector<T>*>(this)->operator[](index);
90 }
91
92 template<typename T1>
93 void output(const Vector<T1>& v) {
94 for (int i = 0; i < v.size; ++i) {
95 cout << v.at(i) << ", ";
96 }
97 cout << "\b\b \n";
98 }
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) { // 多组输入，按下Ctrl + Z终止
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 }
View Code
result4
task5
Student.hpp
1 #pragma once
2
3 #include <iostream>
4 #include <string>
5 #include <iomanip>
6
7 using std::ostream;
8 using std::istream;
9 using std::string;
10 using std::setiosflags;
11 using std::setw;
12 using std::ios_base;
13
14
15
16 class Student {
17 public:
18 Student() = default;
19 ~Student() = default;
20
21 string get_major() const;
22 int get_score() const;
23
24 friend ostream& operator<<(ostream& out, const Student& s);
25 friend istream& operator>>(istream& in, Student& s);
26 private:
27 string no;
28 string name;
29 string major;
30 int score;
31 };
32
33 string Student::get_major() const {
34 return major;
35 }
36
37 int Student::get_score() const {
38 return score;
39 }
40
41
42 ostream& operator<<(ostream& out, const Student& s) {
43 out << setiosflags(ios_base::left);
44 out << setw(15) << s.no
45 << setw(15) << s.name
46 << setw(15) << s.major
47 << setw(15) << s.score;
48
49 return out;
50 }
51
52 istream& operator>>(istream& in, Student& s) {
53 in >> s.no >> s.name >> s.major >> s.score;
54
55 return in;
56 }
utils.hpp
1 #include "Student.hpp"
2 #include <fstream>
3 #include <iostream>
4 #include <vector>
5 #include <string>
6
7 bool compare_by_solutionInfo(const Student& s1, const Student& s2) {
8 if (s1.get_major() < s2.get_major())
9 return true;
10
11 if (s1.get_major() == s2.get_major())
12 return s1.get_score() > s2.get_score();
13
14 return false;
15 }
16
17 // 把vector<Student>对象中的元素插入到输出流out
18 void output(std::ostream& out, const std::vector<Student>& v) {
19 for (auto& i : v) {
20 out << i << std::endl;
21 }
22 }
23
24 // 把vector<Student>对象中的元素写到filename文件中
25 void save(const std::string& filename, std::vector<Student>& v) {
26 using std::ofstream;
27
28 ofstream out(filename);
29 if (!out.is_open()) {
30 std::cout << "fail to open file to write\n";
31 return;
32 }
33
34 output(out, v);
35 out.close();
36 }
37
38 // 从文件filename读取参赛选手信息到vector<Student>对象
39 void load(const std::string& filename, std::vector<Student>& v) {
40 using std::ifstream;
41
42 ifstream in(filename);
43 if (!in.is_open()) {
44 std::cout << "fail to open file to read\n";
45 return;
46 }
47
48 std::string title_line;
49 getline(in, title_line); // 跳过标题行
50
51 Student t;
52 while (in >> t) {
53 v.push_back(t);
54 }
55
56 in.close();
57 }
task5.cpp
1 #include "Student.hpp"
2 #include "utils.hpp"
3 #include <iostream>
4 #include <vector>
5 #include <algorithm>
6
7 void test() {
8 using namespace std;
9
10 vector<Student> v;
11
12 load("data.txt", v);
13 sort(v.begin(), v.end(), compare_by_solutionInfo);
14 output(cout, v);
15 save("ans.txt", v);
16 }
17
18 int main() {
19 test();
20 }
result5
标签：std,文件,const,index,int,Vector,实验,模板,size From： https://www.cnblogs.com/nuist0415/p/18612952