task4:
Vector.hpp源代码:
1 #include<iostream>
2
3 using namespace std;
4
5 template <typename T>
6 class Vector
7 {
8 public:
9 Vector(int nn) :n{ nn } {
10 if (n < 0)throw length_error("Vector: negative size");
11 elem = (T*)malloc(n * sizeof(T));
12 if (!elem)exit(OVERFLOW);
13 }
14 Vector(int nn,T val) :n{ nn } {
15 if (n < 0)throw length_error("Vector: negative size");
16 elem = (T*)malloc(n * sizeof(T));
17 if (!elem)exit(OVERFLOW);
18 for (int i=0;i<n;i++)
19 {
20 elem[i] = val;
21 }
22 }
23 Vector(const Vector<T>& b){
24 n = b.n;
25 elem = (T*)malloc(n * sizeof(T));
26 if (!elem)exit(OVERFLOW);
27 for(int i=0;i<n;i++)
28 {
29 elem[i] = b.elem[i];
30 }
31 }
32 ~Vector() {
33 n = 0;
34 free(elem);
35 }
36 int getsize()
37 {
38 return n;
39 }
40 T& at(int i)
41 {
42 if (i < 0||i>=n)throw out_of_range("Vector: index out of range");
43 return elem[i];
44 }
45 T& operator[](int i)
46 {
47 if (i < 0 || i>=n)throw out_of_range("Vector: index out of range");
48 return elem[i];
49 }
50 template <typename T1>
51 friend void output(const Vector<T1> a);
52 private:
53 T* elem;
54 int n;
55 };
56 template <typename T>
57 void output(const Vector<T> a)
58 {
59 for (int i=0;i<a.n;i++)
60 {
61 cout << a.elem[i] << " ";
62 }
63 cout << endl;
64 }
View Code
task4.cpp源代码:
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 }
View Code
运行结果：
task5: task5.cpp源码：
1 #include <iostream>
2 #include <iomanip>
3 #include <string>
4 #include<vector>
5 #include <fstream>
6 #include <algorithm>
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 class student {
17 public:
18 student() = default;
19 ~student() = default;
20 int get_score() const { return s; }
21 friend ostream& operator<<(ostream& out, const student& c);
22 friend istream& operator>>(istream& in, student& c);
23 friend bool cmp1(student& a, student& b);
24 friend bool cmp2(student& a, student& b);
25 private:
26 string no; // 学号
27 string name; // 姓名
28 string major; // 专业
29 int s; // 解题数
30 };
31 ostream& operator<<(ostream& out, const student& c) {
32 out << setiosflags(ios_base::left);
33 out << setw(15) << c.no
34 << setw(20) << c.name
35 << setw(15) << c.major
36 << setw(5) << c.s;
37 return out;
38 }
39 istream& operator>>(istream& in, student& c) {
40 in >> c.no >> c.name >> c.major >> c.s;
41 return in;
42 }
43
44 void output(std::ostream& out, const std::vector<student>& v) {
45 for (auto& i : v)
46 out << i << std::endl;
47 }
48 void save(const std::string& filename, std::vector<student>& v) {
49 using std::ofstream;
50 ofstream out(filename);
51 if (!out.is_open()) {
52 std::cout << "fail to open file to write\n";
53 return;
54 }
55 output(out, v);
56 out.close();
57 }
58
59 void load(const std::string& filename, std::vector<student>& v) {
60 using std::ifstream;
61 ifstream in(filename);
62 if (!in.is_open()) {
63 std::cout << "fail to open file to read\n";
64 return;
65 }
66 std::string title_line;
67 getline(in, title_line);
68 student t;
69 while (in >> t)
70 v.push_back(t);
71 in.close();
72 }
73 bool cmp1(student& a, student& b)
74 {
75 return a.major.compare(b.major) < 0;
76 }
77 bool cmp2(student& a, student& b)
78 {
79 return a.s > b.s;
80 }
81 void Sort(std::vector<student>& v)
82 {
83 sort(v.begin(), v.end(), cmp2);
84 sort(v.begin(), v.end(), cmp1);
85 }
86 void test() {
87 using namespace std;
88 vector<student> v;
89 load("data5.txt", v);
90 Sort(v);
91 output(cout, v);
92 save("ans5.txt", v);
93 }
94 int main() {
95 test();
96 }
View Code
date5.txt：
运行结果：
标签：std,文件,int,Vector,实验,student,using,include,模板 From： https://www.cnblogs.com/the-existent/p/18611093