实验三 类和对象2
实验任务4
vector_int.h
#ifndef VECTOR_H #define VECTOR_H #include<iostream> #include<cassert> using namespace std; class Vector_int { public: Vector_int(int n); Vector_int(int n, int a); Vector_int(const Vector_int &x); ~Vector_int(); int &at(int x); private: int size; int* p; }; Vector_int::Vector_int(int n) :size{ n } { cout << "构造函数调用" << endl; p = new int[n]; } Vector_int::Vector_int(int n, int s) : size{ n } { cout << "构造函数调用" << endl; p = new int[n]; for (int i = 0; i < n; i++) p[i] = s; } Vector_int::Vector_int(const Vector_int& x) : size{ x.size } { cout << "复制构造函数调用" << endl; p = new int[size]; for (int i = 0; i < size; i++) p[i] = x.p[i]; } int &Vector_int::at(int x)//返回元素引用 { assert(x >= 0 && x < size); return p[x]; } Vector_int::~Vector_int() { cout << "析构函数调用" << endl; delete[] p; } #endif
main.cpp
#include"Vector.h" #include<iostream> using namespace std; int main() { Vector_int a(6); Vector_int b(6, 8); Vector_int c(b); cout << c.at(4) << endl; c.at(5) = 999; cout << c.at(5) << endl; return 0; }
实验结果截图
实验任务5
matrix.h
#ifndef MATRIX_H #define MATRIX_H #include <cassert> #include <iostream> class Matrix { public: Matrix(int n); // 构造函数，构造一个n*n的矩阵 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵 Matrix(const Matrix& X); // 复制构造函数，使用已有的矩阵X构造 ~Matrix(); //析构函数 void set(const double* pvalue); // 用pvalue指向的连续内存块数据为矩阵赋值 void set(int i, int j, int value); //设置矩阵第i行第j列元素值为value double& at(int i, int j); //返回矩阵第i行第j列元素的引用 double at(int i, int j) const; // 返回矩阵第i行第j列元素的值 int get_lines() const; //返回矩阵行数 int get_cols() const; //返回矩列数 void print() const; // 按行打印输出矩阵 private: int lines; // 矩阵行数 int cols; // 矩阵列数 double* p; // 指向存放矩阵数据的内存块的首地址 }; // 类Matrix的实现：待补足 // ××× Matrix::Matrix(int n):lines{n},cols{n} { p = new double[lines*cols]; } Matrix::Matrix(int n, int m) : lines{ n }, cols{ m } { p = new double[lines*cols]; } Matrix::Matrix(const Matrix& X):lines{X.lines},cols{X.cols} { p = new double[lines * cols]; for (int i = 0; i < lines; i++) { for (int j = 0; j < cols; j++) { p[i*cols + j] = X.p[i*cols + j]; } } } Matrix::~Matrix() { delete[]p; } void Matrix::set(const double* pvalue) { int t = sizeof(pvalue); int s = 0; while (s<=t) { for (int i = 0; i < lines; i++) { for (int j = 0; j < cols; j++) { p[i * cols + j] = pvalue[s]; s++; } } } } void Matrix::set(int i, int j, int value) { p[i * cols + j] = value; } double& Matrix::at(int i, int j) { return p[i * cols + j]; } double Matrix::at(int i, int j) const { return p[i * cols + j]; } int Matrix::get_lines() const { return lines; } int Matrix::get_cols() const { return cols; } void Matrix::print() const { for (int i = 0; i < lines; i++) { for (int j = 0; j < cols; j++) { std::cout << p[i * cols + j] << ", "; } std::cout << std::endl; } } #endif
task5.cpp
#include <iostream> #include "Matrix.h" int main() { using namespace std; double x[] = {1,2,3,4,5,6}; Matrix m1(3, 2); // 创建一个3×2的矩阵 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值 m1.print(); // 打印矩阵m1的值 cout << "the first line is: " << endl; cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl; cout << endl; Matrix m2(2, 3); m2.set(x); m2.print(); cout << "the first line is: " << endl; cout << m2.at(0, 0) << " " << m2.at(0, 1) << " " << m2.at(0, 2) << endl; cout << endl; Matrix m3(m2); m3.set(0, 0, 999); m3.print(); }
更换了x数组的数据为4,6,8,10,12,14
#include <iostream> #include "Matrix.h" int main() { using namespace std; double x[] = {4,6,8,10,12,14}; Matrix m1(3, 2); // 创建一个3×2的矩阵 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值 m1.print(); // 打印矩阵m1的值 cout << "the first line is: " << endl; cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl; cout << endl; Matrix m2(2, 3); m2.set(x); m2.print(); cout << "the first line is: " << endl; cout << m2.at(0, 0) << " " << m2.at(0, 1) << " " << m2.at(0, 2) << endl; cout << endl; Matrix m3(m2); m3.set(0, 0, 999); m3.print(); }
实验结果截图
