# include<iostream.h>
    # include<conio.h>
    # include<process.h>
    # include<ctype.h>
    # include<iomanip.h>

    class Matrix
    {
        float row,col;
        float **arr;
      public:
        Matrix();
        Matrix(float,float);
        Matrix(Matrix &);
//        ~Matrix();void inputDim(float,float);
        Matrix inverse();
        Matrix operator+(Matrix &);
        Matrix operator-(Matrix &);
        Matrix operator*(Matrix &);
        floatoperator==(Matrix &);
        voidoperator+=(Matrix &);
        friend voidoperator<<(ostream &,Matrix &);
        friend voidoperator>>(istream &,Matrix &);
    };

    Matrix::Matrix()
    {
        row=col=0;
        arr=NULL;
    }

    Matrix::Matrix(float row,float col)
    {
        this->row=row;
        this->col=col;
        arr=newfloat*[row];
        for(float i=0;i<row;i++)
            arr[i]=newfloat[col];
    }

    Matrix::Matrix(Matrix &t)
    {
        this->row=t.row;
        this->col=t.col;
        this->arr=newfloat*[t.row];
        for(float i=0;i<t.row;i++)
            this->arr[i]=newfloat[t.col];

        for(float j=0;j<t.row;j++)
            for(float k=0;k<col;k++)
                this->arr[j][k]=t.arr[j][k];
    }
/*
    Matrix::~Matrix()
    {
        delete arr;
    }
*/


    Matrix Matrix::inverse()
    {
            float temp,tt;
            Matrix t,x;
            x=*this;
            t.inputDim(this->row,this->col);

            for(int i=0;i<this->row;i++)
            {
                for(int j=0;j<this->col;j++)
                {
                    if(i==j)
                        t.arr[i][j]=1;
                    else
                        t.arr[i][j]=0;
                }
            }
            for(i=0;i<t.row;i++)
            {
                temp=x.arr[i][i];
                if(temp==0)
                {
                    for(int j=0;j<t.col;j++)
                    {
                        tt=x.arr[i][j];
                        x.arr[i][j]=x.arr[i+1][j];
                        x.arr[i+1][j]=tt;

                        tt=t.arr[i][j];
                        t.arr[i][j]=t.arr[i+1][j];
                        t.arr[i+1][j]=tt;
                    }
                }
                //Step 1:for(int j=0;j<t.col;j++)
                {
                    x.arr[i][j]/=temp;
                    t.arr[i][j]/=temp;
                }
                cout<<endl<<"MATRIX A"<<endl;
                cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍ"<<endl;
                cout<<x;
                cout<<endl<<"MATRIX B"<<endl;
                cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍ"<<endl;
                cout<<t;
                getch();
                //Step 2:for(int k=0;k<t.row;k++)
                {
                    temp=x.arr[k][i];
                    if(k!=i)
                    {
                        for(j=0;j<t.col;j++)
                        {
                            t.arr[k][j]+=(t.arr[i][j]*(-temp));
                            x.arr[k][j]+=(x.arr[i][j]*(-temp));
                        }
                    }
                }
                cout<<endl<<"MATRIX A"<<endl;
                cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍ"<<endl;
                cout<<x;
                cout<<endl<<"MATRIX B"<<endl;
                cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍ"<<endl;
                cout<<t;
                getch();
            }
            return t;
    }
    void Matrix::inputDim(float row,float col)
    {
        this->row=row;
        this->col=col;
        this->arr=newfloat*[row];
        for(float i=0;i<row;i++)
            this->arr[i]=newfloat[col];
    }

    float Matrix::operator==(Matrix &t)
    {
        if(this->row!=t.row || this->col!=t.col)
        {
            cout<<endl<<"Comparison not possible";
            getch();
    //        exit(1);
        }
        for(float i=0;i<this->row;i++)
        {
            for(float j=0;j<this->col;j++)
            {
                if(this->arr[i][j]!=t.arr[i][j])
                    return 0; //Unequal Matrix;
            }
        }
        return 1;  //Equal Matrix;
    }

    Matrix Matrix::operator+(Matrix &m)
    {
        if(this->row==m.row && this->col==m.col)
        {
            Matrix t;
            t.inputDim(m.row,m.col);
            for(float i=0;i<m.row;i++)
                for(float j=0;j<m.col;j++)
                    t.arr[i][j]=this->arr[i][j]+m.arr[i][j];
            return t;
        }
        else
        {
            cout<<endl<<"Addition is not possible : ";
            getch();
//            exit(1);
        }
    }

    void Matrix::operator+=(Matrix &m)
    {
        if(this->row==m.row && this->col==m.col)
        {
            for(float i=0;i<m.row;i++)
                for(float j=0;j<m.col;j++)
                    this->arr[i][j]+=m.arr[i][j];
        }
        else
        {
            cout<<endl<<"Addition is not possible : ";
            getch();
    //        exit(1);
        }
    }

    Matrix Matrix::operator-(Matrix &m)
    {
        if(this->row==m.row && this->col==m.col)
        {
            Matrix t;
            t.inputDim(m.row,m.col);
            for(float i=0;i<m.row;i++)
                for(float j=0;j<m.col;j++)
                    t.arr[i][j]=this->arr[i][j]-m.arr[i][j];
            return t;
        }
        else
        {
            cout<<endl<<"Subtraction is not possible : ";
            getch();
    //        exit(1);
        }
    }

    Matrix Matrix::operator*(Matrix &m)
    {
        if(this->col==m.row)
        {
            Matrix t;
            t.inputDim(this->row,m.col);
            for(float i=0;i<this->row;i++)
            {
                for(float j=0;j<m.col;j++)
                {
                    t.arr[i][j]=0;
                    for(float k=0;k<m.row;k++)
                        t.arr[i][j]+=this->arr[i][k]*m.arr[k][j];
                }
            }
            return t;
        }
        else
        {
            cout<<endl<<"Addition is not possible : ";
            getch();
    //        exit(1);
        }
    }

    voidoperator<<(ostream &mycout,Matrix &t)
    {
        for(float i=0;i<t.row;i++)
        {
            cout.width(4);
            cout.precision(2);
            for(float j=0;j<t.col;j++)
                mycout<<setw(5)<<t.arr[i][j]<<" ";
            mycout<<endl;
        }
    }

    voidoperator>>(istream &mycin,Matrix &t)
    {
        for(float i=0;i<t.row;i++)
        {
            for(float j=0;j<t.col;j++)
            {
                cout<<endl<<"Enter m["<<i+1<<"]["<<j+1<<"] : ";
                mycin>>t.arr[i][j];
            }
        }
    }

    void main()
    {
        int r,c,choice,DataEntered=0;
        Matrix a,b,x;
        void getDimension(int &,int &);
        void showResult(Matrix &,Matrix &,Matrix &);
        void showResult1(Matrix &,Matrix &);
        char ch='Y';
        do
        {
            clrscr();
            gotoxy(20,6);
            cout<<"Matrix Operations";
            gotoxy(20,7);
            cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";
            gotoxy(20,8);
            cout<<"Create two new matricies  : 1";
            gotoxy(20,9);
            cout<<"Matrix addition           : 2";
            gotoxy(20,10);
            cout<<"Matrix addition using +=  : 3";
            gotoxy(20,11);
            cout<<"Matrix subtraction        : 4";
            gotoxy(20,12);
            cout<<"Matrix multiplicaton      : 5";
            gotoxy(20,13);
            cout<<"Matrix Equality checking  : 6";
            gotoxy(20,14);
            cout<<"Show both Matrices        : 7";
            gotoxy(20,15);
            cout<<"Inverse Matrix            : 8";
            gotoxy(20,16);
            cout<<"Exit                      : 0";
            gotoxy(20,17);
            cout<<"Select your choice        : ";
            cin>>choice;
            clrscr();
/*            if(!DataEntered && choice!=1 && choice !=0)
            {
                cout<<endl<<"Matrices are empty";
                getch();
                continue;
            }
*/
switch(choice)
            {
                case 1:
                    cout<<endl<<"Matrix-A Details";
                    cout<<endl<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";
                    getDimension(r,c);
                    a = Matrix(r,c);
                    cin>>a;

                    cout<<endl<<"Matrix-B Details";
                    cout<<endl<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";
                    getDimension(r,c);
                    b = Matrix(r,c);
                    cin>>b;
                    DataEntered=1;
                    break;
                case 2:
                    x=a+b;
                    showResult(a,b,x);
                    break;
                case 3:
                    a+=b;
                    showResult1(a,b);
                    break;
                case 4:
                    x=a-b;
                    showResult(a,b,x);
                    break;
                case 5:
                    Matrix x=a*b;
                    showResult(a,b,x);
                    break;
                case 6:
                    if(a==b)
                        cout<<"Both matrix are equal";
                    else
                        cout<<"Both matrix are unequal";
                    break;
                case 7:
                    showResult1(a,b);
                    break;
                case 8:
                    cout<<endl<<"Matrix-A Details";
                    cout<<endl<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";
                    getDimension(r,c);
                    a = Matrix(r,c);
                    cin>>a;

                    b = a.inverse();
                    showResult1(a,b);
                case 0:
                    exit(1);
                default:
                    gotoxy(20,16);
                    cout<<"Invalid selection";
            }
            cout<<endl<<"continue (y/n) : ";
            cin>>ch;
            ch=toupper(ch);
        }while(ch=='Y');
        getch();
    }

    void getDimension(int &r,int &c)
    {
        cout<<endl<<"Enter row dimension : ";
        cin>>r;
        cout<<endl<<"Enter col dimension : ";
        cin>>c;
    }

    void showResult(Matrix &x,Matrix &y,Matrix &z)
    {
        clrscr();
        cout<<endl<<"Matrix A";
        cout<<endl<<"ÍÍÍÍÍÍÍÍ"<<endl;
        cout<<x;
        cout<<endl<<"Matrix B";
        cout<<endl<<"ÍÍÍÍÍÍÍÍ"<<endl;
        cout<<y;
        cout<<endl<<"Result";
        cout<<endl<<"ÍÍÍÍÍÍ"<<endl;
        cout<<z;
    }

    void showResult1(Matrix &x,Matrix &y)
    {
        clrscr();
        cout<<endl<<"Matrix A";
        cout<<endl<<"ÍÍÍÍÍÍÍÍ"<<endl;
        cout<<x;
        cout<<endl<<"Matrix B";
        cout<<endl<<"ÍÍÍÍÍÍÍÍ"<<endl;
        cout<<y;
    }

    /* OUTPUT

                   Matrix Operations
                   ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ
                   Create two new matricies  : 1
                   Matrix addition           : 2
                   Matrix addition using +=  : 3
                   Matrix subtraction        : 4
                   Matrix multiplicaton      : 5
                   Matrix Equality checking  : 6
                   Show both Matrices        : 7
                   Exit                      : 0
                   Select your choice        : 5

                   Multiplication.

                   Matrix A
                   ÍÍÍÍÍÍÍÍ
                   1 2 3
                   4 5 6

                   Matrix B
                   ÍÍÍÍÍÍÍÍ
                   1 2
                   3 4
                   5 6

                   Result
                   ÍÍÍÍÍÍ
                   22 28
                   49 64

                   continue (y/n) :
    */