1 #pragma once
2 #include<iostream>
3 using namespace std;
4 class vectorInt
5 {
6 public:
7 friend void output(vectorInt& x);
8 vectorInt(int n);
9 vectorInt(int n, int value);
10 vectorInt(const vectorInt& r);
11 //vectorInt(vectorInt&& r) = delete;
12 ~vectorInt();
13 int& at(int i);
14 int get_size();
15 private:
16 int size;
17 int* p;
18 };
19 vectorInt::vectorInt(int n) :size(n)
20 {
21 cout << "constructor 1 called." << endl;
22 p = new int[n];
23 }
24 vectorInt::vectorInt(int n, int value) :size(n)
25 {
26 cout << "constructor 2 called." << endl;
27 p = new int[n];
28 for (int i = 0; i < size; i++)
29 {
30 p[i] = value;
31 }
32 }
33 vectorInt::vectorInt(const vectorInt& r) :size{ r.size }
34 {
35 cout << "copy constructor called." << endl;
36 p = new int[size];
37 for (int i = 0; i < size; i++)
38 p[i] = r.p[i];
39 }
40 vectorInt::~vectorInt()
41 {
42 cout << "destructor called." << endl;
43 delete[] p;
44 }
45 int& vectorInt::at(int i)
46 {
47 return p[i];
48 }
49 int vectorInt::get_size()
50 {
51 return size;
52 }
53 void output(vectorInt& x)
54 {
55 /*for (int i = 0; i < x.size; i++)
56 {
57 cout <<*(x.p) << " ";
58 (x.p)++;
59 }*/
60 for (int i = 0; i < x.size; i++)
61 cout << x.p[i] << " ";
62 cout << endl;
63 }
#include <iostream>
#include "vectorInt.h"
void test()
{
using namespace std;
int n;
cin >> n;
vectorInt x1(n);
for (auto i = 0; i < n; ++i)
x1.at(i) = i * i;
output(x1);
vectorInt x2(n, 42);
vectorInt x3(x2);
output(x2);
output(x3);
x2.at(0) = 77;
output(x2);
output(x3);
}
int main()
{
test();
}
1 #pragma once
2 #include <iostream>
3 using std::cout;
4 using std::endl;
5 class Matrix
6 {
7 public:
8 Matrix(int n); // 构造函数，构造一个n*n的矩阵
9 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵
10 Matrix(const Matrix& X); // 复制构造函数，使用已有的矩阵X构造
11 ~Matrix(); //析构函数
12
13 void set(const double* pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值
14 void set(int i, int j, int value); //设置矩阵第i行第j列元素值为value
15 double& at(int i, int j); //返回矩阵第i行第j列元素的引用
16 double at(int i, int j) const; // 返回矩阵第i行第j列元素的值
17 int get_lines() const; //返回矩阵行数
18 int get_cols() const; //返回矩列数
19 void print() const; // 按行打印输出矩阵
20
21 private:
22 int lines; // 矩阵行数
23 int cols; // 矩阵列数
24 double* p; // 指向存放矩阵数据的内存块的首地址
25 };
26 Matrix::Matrix(int n) :lines(n), cols(n)
27 {
28 p = new double[n * n];
29 }
30 Matrix::Matrix(int n, int m) :lines(n), cols(m)
31 {
32 p = new double[n * m];
33 }
34 Matrix::Matrix(const Matrix& X) :lines(X.lines), cols(X.cols)
35 {
36 p = new double[X.lines * X.cols];
37 for (int i = 0; i < X.lines * X.cols; i++)
38 p[i] = X.p[i];
39 }
40 Matrix::~Matrix()
41 {
42 delete[]p;
43 }
44 void Matrix::set(const double* pvalue)
45 {
46 for (int i = 0; i < lines * cols; i++)
47 p[i] = pvalue[i];
48 }
49 void Matrix::set(int i, int j, int value)
50 {
51 p[i * cols + j] = value;
52 }
53 double& Matrix::at(int i, int j)
54 {
55 return p[i * cols + j];
56 }
57 double Matrix::at(int i, int j) const
58 {
59 return p[i * cols + j];
60 }
61 int Matrix::get_lines() const
62 {
63 return lines;
64 }
65 int Matrix::get_cols() const
66 {
67 return cols;
68 }
69 void Matrix::print() const
70 {
71 for (int i = 0; i < lines * cols; i++)
72 {
73 cout << p[i] << " ";
74 if ((i + 1) % cols == 0)
75 cout << endl;
76 }
77 }
1 #include <iostream>
2 #include "matrix.h"
3
4 void test() {
5 using namespace std;
6
7 double x[] = { 2, 3, 4, 5, 6,7 };
8
9 Matrix m1(3, 2); // 创建一个3×2的矩阵
10 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
11 m1.print(); // 打印矩阵m1的值
12 cout << "the first line is: " << endl;
13 cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl; // 输出矩阵m1第1行两个元素的值
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, 0) << " " << m2.at(0, 1) << " " << m2.at(0, 2) << endl;
21 cout << endl;
22
23 Matrix m3(m2); // 用矩阵m2构造新的矩阵m3
24 m3.set(0, 0, 888); // 将矩阵m3第0行第0列元素值设为888
25 m3.print();
26 }
27
28 int main() {
29 test();
30 }
