matran

#include <iostream>
#include <conio.h>
#include <math.h>
#include <iomanip>

using namespace std;

struct matran {
    int n;
    int **a;
};

void nhap(matran &a)
{
    cout << "Nhap cap ma tran: ";
    cin >> a.n;
    a.a = new int*[a.n];
    for (int i=0; i<a.n; i++)
    a.a[i] = new int[a.n];
    for (i=0; i<a.n; i++)
        for (int j=0; j<a.n; j++)
        {
            cout << "Nhap a[" << i+1 << "][" << j+1 << "]: ";
            cin >> a.a[i][j];
        }
}

void in (matran a)
{
    for (int i=0; i<a.n; i++)
    {
        for (int j=0; j<a.n; j++)
        cout << setw(6) << a.a[i][j];
        cout << endl;
    }
}

matran operator - (matran a)
{
    int i;
    matran b;
    b.n = a.n;
    b.a = new int*[b.n];
    for (i=0; i<b.n; i++)
    b.a[i] = new int [b.n];
    for (i=0; i<b.n; i++)
        for (int j=0; j<b.n; j++)
            b.a[i][j] = -a.a[i][j];
    return b;
}

main ()
{
    matran a,b;
    nhap(a);
    cout << endl << "Ma tran A: " << endl;
    in(a);
    b=-a;
    cout << endl << "Ma tran B: " << endl;
    in(b);
    getch();
}