第9周任务4

来源：互联网发布：java实用教程第三版pdf 编辑：程序博客网时间：2024/05/21 13:26
#include <iostream>   using namespace std;  #include "p.h"  class Douary  {  public:      Douary(int m, int n);//构造函数：用于建立动态数组存放m行n列的二维数组（矩阵）元素，并将该数组元素初始化为       Douary(const Douary &d);//构造函数：用于建立动态数组存放m行n列的二维数组（矩阵）元素，并将该数组元素初始化为       ~Douary(); //析构函数：用于释放动态数组所占用的存储空间       friend istream &operator>>(istream &input, Douary &d);//重载运算符“>>”输入二维数组，其中d为Dousry类对象；       friend ostream &operator<<(ostream &output, Douary &d);//重载运算符“<<”以m行n列矩阵的形式输出二维数组，其中d为Douary类对象。       friend Douary operator+(const Douary &d1,const Douary &d2);//两个矩阵相加，规则：对应位置上的元素相加       friend Douary operator-(const Douary &d1,const Douary &d2);//两个矩阵相减，规则：对应位置上的元素相减       bool operator==(const Douary &d);//判断两个矩阵是否相等，即对应位置上的所有元素是否相等   private:      int * Array;      //Array 为动态数组指针。       int row;          //row  为二维数组的行数。       int col;          //col   为二维数组的列数。   };  Douary::Douary(int m, int n)  {      row=m;      col=n;      Array = new int[m*n];     for(int i=0; i<row; i++)          for(int j=0; j<col; j++)              Array[i*col+j]=0; }    Douary::Douary(const Douary &d)  {      row=d.row;      col=d.col;      Array = new int[row*col];      for(int i=0; i<row; i++)   {        for(int j=0; j<col; j++)   {            Array[i*col+j]=d.Array[i*col+j];   } }}    Douary::~Douary() //析构函数：用于释放动态数组所占用的存储空间   {      delete [] Array;  }    istream &operator>>(istream &input, Douary &d) {      for(int i=0; i<d.row; ++i)  {        for(int j=0; j<d.col; ++j)    {            cin>>d.Array[i*d.col+j];    } }    return input;  }    ostream &operator<<(ostream &output, Douary &d)  {      for(int i=0; i<d.row; ++i)      {          for(int j=0; j<d.col; ++j)              cout<<d.Array[i*d.col+j]<<"\t";         cout<<endl;      }      cout<<endl;      return output;  }    Douary operator+(const Douary &d1,const Douary &d2)//两个矩阵相加，规则：对应位置上的元素相加   {             Douary d(d1.row,d1.col);      for(int i=0; i<d1.row; ++i)      {          for(int j=0; j<d1.col; ++j)              d.Array[i*d1.col+j]=d1.Array[i*d1.col+j]+d2.Array[i*d1.col+j];      }      return d;  }    Douary operator-(const Douary &d1,const Douary &d2)//两个矩阵相减，规则：对应位置上的元素相减   {         Douary d(d1.row,d1.col);      for(int i=0; i<d1.row; ++i)      {          for(int j=0; j<d1.col; ++j)    {            d.Array[i*d1.col+j]=d1.Array[i*d1.col+j]-d2.Array[i*d1.col+j];    }    }      return d;  }  bool Douary::operator ==(const Douary &d)//判断两个矩阵是否相等，即对应位置上的所有元素是否相等   {      if(row!=d.row||col!=d.col)   return false;      bool flag = true;      for(int i=0; i<row; ++i)      {          for(int j=0; j<col; ++j)    {            if (Array[i*col+j]!=d.Array[i*col+j])               {                  flag=false;                  break;              }              //if (!flag) break;    }    }      return flag;  }    int main()  {      Douary d1(3,5),d2(3,5);      cout<<"输入d1(3,5):"<<endl;      cin>>d1;      cout<<"输入d2(3,5):"<<endl;      cin>>d2;      cout<<"d1="<<endl;      cout<<d1;      cout<<"d2="<<endl;      cout<<d2;      cout<<"d1+d2="<<endl;      Douary d3=(d1+d2);      cout<<d3;      cout<<"d1-d2="<<endl;      cout<<(d1-d2);      cout<<"d1"<<((d1==d2)?"==":"!=")<<"d2"<<endl;      system("pause");      return 0;  }
感悟：
老师：if (!flag) break 是啥意思啊？没有它不也行吗？