实验4 类与数组 指针

实验五：

vectorInt.hpp

 1 #pragma once
 2 #include<cassert>
 3 using namespace std;
 4 
 5 class vectorInt{
 6     public:
 7         vectorInt(int n);
 8         vectorInt(int n,int value);
 9         vectorInt(const vectorInt &);
10         ~vectorInt(){
11             delete p;
12             cout << "destructor called" << endl;
13         }
14         int &at(int index);
15         int get_size(){
16             return size;
17         }
18         friend void output(vectorInt &v);
19             
20     private:
21         int size;
22         int *p;
23         
24 };
25 int &vectorInt::at(int index){
26     assert(index>=0&&index<size);
27     return p[index];
28 }
29 
30 vectorInt::vectorInt(int n):size{n}{
31         p=new int[size];
32     cout << "constructor 1 called" << endl;
33 };
34 
35 vectorInt::vectorInt(int n,int value):size{n}{
36     p=new int[size];
37     for(int i=0;i<size;i++){
38         p[i]=value;
39     }
40     cout << "constructor 2 called" << endl;
41 }
42 
43 vectorInt::vectorInt(const vectorInt &a):size{a.size}{
44     p=new int[size];
45     for(int i=0;i<size;i++){
46         p[i]=a.p[i];
47     }
48     cout << "copy constructor called" << endl;
49 }
50     
51 void output(vectorInt &v){
52     int i;
53     for(i=0;i<v.size-1;i++){
54         cout << v.p[i] << ",";
55     }
56     cout << v.p[v.size-1] << endl;
57 }

task5.cpp

 1 #include <iostream>
 2 #include "vectorInt.hpp"
 3 
 4 void test() {
 5     using namespace std;
 6 
 7     int n;
 8     cin >> n;
 9     
10     vectorInt x1(n);
11     for(auto i = 0; i < n; ++i)
12         x1.at(i) = i*i;
13 
14     output(x1);
15 
16     vectorInt x2(n, 42);
17     vectorInt x3(x2);
18 
19     output(x2);
20     output(x3);
21 
22     x2.at(0) = 77;
23 
24     output(x2);
25     output(x3);
26 }
27 
28 int main() {
29     test();
30 }

实验六：

Matrix.hpp

 1 #pragma once
 2 #include <iostream>
 3 using std::cout;
 4 using std::endl;
 5 class Matrix {
 6 public:
 7     Matrix(int n);                     // 构造函数，构造一个n*n的矩阵
 8     Matrix(int n, int m);              // 构造函数，构造一个n*m的矩阵
 9     Matrix(const Matrix &X);           // 复制构造函数，使用已有的矩阵X构造
10     ~Matrix();                         //析构函数
11 
12     void set(const double *pvalue);     // 用pvalue指向的连续内存块数据按行为矩阵赋值
13     void set(int i, int j, int value); //设置矩阵第i行第j列元素值为value
14     double &at(int i, int j);          //返回矩阵第i行第j列元素的引用
15     double at(int i, int j) const;     // 返回矩阵第i行第j列元素的值
16     int get_lines() const;             //返回矩阵行数
17     int get_cols() const;              //返回矩列数
18     void print() const;                // 按行打印输出矩阵
19 
20 private:
21     int lines; // 矩阵行数
22     int cols;  // 矩阵列数
23     double *p; // 指向存放矩阵数据的内存块的首地址
24 };
25 
26 Matrix::Matrix(int n):lines{n},cols{n}{
27     p=new double[n*n];
28 }
29 
30 Matrix::Matrix(int n,int m):lines{n},cols{m}{
31     p=new double[n*m];
32 }
33 
34 Matrix::Matrix(const Matrix &x):lines{x.lines},cols{x.cols}{
35     p=new double[x.lines*x.cols];
36     for(int i=0;i<x.lines;i++){
37         for(int j=0;j<x.cols;j++){
38             p[i*x.cols+j]=x.p[i*x.cols+j];
39         }
40     }
41 }
42 
43 Matrix::~Matrix(){
44     delete p;
45 }
46 
47 void Matrix::set(const double *pvalue){
48     for(int line=0;line<lines;line++){
49         for(int col=0;col<cols;col++){
50             p[line*cols+col]=pvalue[line*cols+col];
51         }    
52         }
53 }
54 
55 void Matrix::set(int i,int j,int value){
56     p[i*cols+j]=value;
57 }
58 
59 double &Matrix::at(int i,int j){
60     return p[i*cols+j];
61 }
62 
63 double Matrix::at(int i,int j)const{
64     return p[i*cols+j];
65 }
66 
67 int Matrix::get_lines()const{
68     return lines;
69 }
70 
71 int Matrix::get_cols()const{
72     return cols;
73 }
74 
75 void Matrix::print() const{
76     int i,j;
77     for(i=0;i<lines;i++){
78         for(j=0;j<cols-1;j++){
79             cout << p[i*cols+j] <<",";
80         }
81         cout << p[i*cols+cols-1] << endl;
82     }
83 }

task6.cpp

 1 #include <iostream>
 2 #include "matrix.hpp"
 3 
 4 void test() {
 5     using namespace std;
 6 
 7     double x[] = {1, 2, 3, 4, 5, 6};
 8 
 9     Matrix m1(3, 2);    
10     m1.set(x);          
11     m1.print();        
12     cout << "the first line is: " << endl;
13     cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl;  
14     cout << endl;
15 
16     Matrix m2(2, 3);
17     m2.set(x);
18     m2.print();
19     cout << "the first line is: " << endl;
20     cout << m2.at(0, 1) << " " << m2.at(0, 2) << " " << m2.at(0, 3) << endl;
21     cout << endl;
22 
23     Matrix m3(m2);      
24     m3.set(0, 0, 888);  
25     m3.print();
26 }
27 
28 int main() {
29     test();
30 }