11.4
#include<iostream> class vector_int { public: vector_int(); vector_int(int n); vector_int(int n, int value); vector_int(vector_int &X); ~vector_int(); int &at(int n); void show(); private: int size; int *array; }; vector_int::vector_int(int n):size(n) { array = new int[n]; } vector_int::vector_int(int n, int value):size(n) { array = new int[n]; for(auto i = 0; i < n ; i++) { array[i] = value; } } vector_int::vector_int(vector_int &X) { size = X.size; array = new int(X.size); for(auto i=0; i<X.size; ++i) array[i] = X.array[i]; } vector_int::~vector_int() { delete[] array; } int &vector_int::at(int n) { return array[n]; } void vector_int::show() { for(auto i=0; i<size; ++i) std::cout << array[i] << " "; std::cout << std::endl; }
#include<iostream> #include"vector_int.hpp" int main() { using namespace std; vector_int x1(3); vector_int x2(3,4); vector_int x3(x2); x3.at(0) = 0; cout << "x2 :"; x2.show(); cout << "x3 :" ; x3.show(); }
#ifndef MATRIX_H #define MATRIX_H #include <iostream> #include <cassert> 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 }; Matrix::Matrix(int n) { lines = n; cols = n; p = new double[n*n]; } Matrix::Matrix(int n, int m) // 构造函数,构造一个n*m的矩阵 { lines = n; cols = m; p = new double[n*m]; } Matrix::Matrix(const Matrix &X) // 复制构造函数,使用已有的矩阵X构造 { lines = X.lines; cols = X.cols; p = new double[lines*cols]; int i,j; for(i = 0; i < lines ;i++) { for(j =0; j < cols ;j++) { p[i*cols+j] = X.p[i*cols+j]; } } } Matrix::~Matrix() //析构函数 { delete[] p; } void Matrix::set(const double *pvalue) // 用pvalue指向的连续内存块数据为矩阵赋值 { int i,j,k = 0; for(i = 0; i < lines ;i++) { for(j =0; j < cols ;j++) { p[i*cols+j] = pvalue[k]; k++; } } } void Matrix::set(int i, int j, int value) //设置矩阵第i行第j列元素值为value { p[i*cols+j] = value; } double &Matrix::at(int i, int j) //返回矩阵第i行第j列元素的引用 { return p[i*cols+j]; } double Matrix::at(int i, int j) const // 返回矩阵第i行第j列元素的值 { return p[i*cols+j]; } int Matrix::get_lines() const //返回矩阵行数 { return lines; } int Matrix::get_cols() const //返回矩列数 { return cols; } void Matrix::print() const { for(auto i = 0; i < lines ;i++) { for(auto j =0; j < cols ;j++) { std::cout << p[i*cols+j] << " "; } std::cout << std::endl; } } #endif
#include <iostream> #include "matrix.hpp" 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(); }
实验总结:
无