任务4：
Vector.hpp
1 #include<bits/stdc++.h>
2 using namespace std;
3 template <typename T>
4 class Vector{
5 public:
6 Vector(int size,int value=0):size{size}{
7 if(size<0) throw length_error("negative size");
8 else{
9 ptr=new T[size];
10 for(int i=0;i<size;i++){
11 ptr[i]=value;
12 }
13 }
14 }
15 int get_size() const{
16 return size;
17 }
18 T& at(int val){
19 if(val>=size) throw out_of_range("index out of range");
20 else return ptr[val];
21 }
22 T& operator[] (int val){
23 if(val<0||val>=size) throw out_of_range("index out of range");
24 else return ptr[val];
25 }
26 friend void output(const Vector<T> &x){
27 for(int i=0;i<x.get_size();i++){
28 cout<<x.ptr[i]<<", ";
29 }
30 cout<<endl;
31 }
32 Vector(const Vector<T>& x):size(x.size),ptr(new T[size]){
33 for(int i=0;i<size;i++){
34 ptr[i]=x.ptr[i];
35 }
36 }
37 private:
38 int size;
39 T* ptr;
40 };
View Code
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) {
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
运行结果截图：
任务5：
task5.cpp
1 #include<bits/stdc++.h>
2 using namespace std;
3 class student{
4 private:
5 string name;
6 string number;
7 int grade;
8 string major;
9 public:
10 student()=default;
11 ~student()=default;
12 string get_major() const{
13 return major;
14 }
15 int get_grade() const{
16 return grade;
17
18 }
19 friend ostream& operator<<(ostream &out,const student &s){
20 out<<setiosflags(ios_base::left);
21 out<<setw(15)<<s.number<<setw(15)<<s.name<<setw(15)<<s.major<<setw(15)<<s.grade;
22 return out;
23 }
24 friend istream &operator>>(istream &in,student &s){
25 in>>s.number>>s.name>>s.major>>s.grade;
26 return in;
27 }
28 };
29
30 void ld(const string &filename,vector<student> &s){
31 ifstream in(filename);
32 if(!in.is_open())
33 {
34 cout<<"file open read\n";
35 return ;
36 }
37 string title_line;
38 getline(in,title_line);
39 student t;
40 while(in>>t)
41 s.push_back(t);
42 in.close();
43 }
44
45 void output(ostream &out,const vector<student> &s){
46 for(auto& i:s)
47 out<<i<<endl;
48 }
49
50 void ew(const string &filename,vector<student> &s){
51 ofstream out(filename);
52 if(!out.is_open()){
53 cout<<"file open write\n";
54 return ;
55
56 }
57 output(out,s);
58 out.close();
59 }
60
61
62 bool compare(student &s1,student &s2){
63 if(s1.get_major()<s2.get_major()) return true;
64 if(s1.get_major()==s2.get_major()) return s1.get_grade()>s2.get_grade();
65 return false;
66 }
67 int main(){
68 vector<student> s;
69 ld("data5.txt",s);
70 sort(s.begin(),s.end(),compare);
71 output(cout,s);
72 ew("data5_2.txt",s);
73 }
74
View Code
运行结果截图：
实验总结：通过这次实验，加深了对模板类使用的理解。
标签：文件,return,cout,int,Vector,实验,size,模板,out From： https://www.cnblogs.com/yhjXW/p/18621775