Matrix

#include<iostream>
#include<fstream>
#include<cmath>
#include<iomanip>
#include<cstring>
using namespace std;
const int lengthColumn = 7;
const int Indent = 4;

void show(int **x, int n)
{
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            cout << x[i][j] << ' ';
        cout << endl;
    }
}

int** create(int n)
{
    int **y = new int *[n];
    for (int i = 0; i < n; i++)
    {
        y[i] = new int[n];
    }
    return y;
}

int** create_mass(ifstream &f, int n,int m)
{
    int **y = new int *[n];
    int i, j;
    for (i = 0; i < n; i++)
    {
        y[i] = new int[m];
    }
    for (i = 0; i < n; i++)
        for (j = 0; j < m; j++)
            f >> y[i][j];
    return y;
}

void star(int n, int m)
{
    cout.width(n);
    for (int i = 0; i < m; i++)
        cout << '*';
    cout << endl;
}

void table(int** x, int n,int m)
{
    int lengthTable = 9;
    for (int i = 0; i < m - 1; i++) {
        lengthTable += 8;
    }
    cout << endl;
    star(Indent, lengthTable);

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout.width(Indent);
            cout << '*';
            cout.width(4);
            cout << x[i][j];
        }
        cout.width(Indent);
        cout << '*';
        cout << endl;
        star(Indent, lengthTable);
    }

}

int** summ(int **a, int **b, int n) {
    int **y = create(n);
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            y[i][j] = a[i][j] + b[i][j];
    return y;
}

int** sub(int **a, int **b, int n) {
    int **y = create(n);
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            y[i][j] = a[i][j] - b[i][j];
    return y;
}

int** mult_on_num(int **a, int n) {
    int num;
    cout << "Enter number: "; cin >> num;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            a[i][j] *= num;
    return a;
}

int** transp(int** a, int n) {
    for (int i = 0; i < n; i++)
        for (int j = i; j < n; j++)
            swap(a[i][j], a[j][i]);
    return a;
}

int** mult(int **a, int **b, int n, int m, int q) {
    int **y = create(n+1);

    for (int i = 0; i < m; i++)
        for (int j = 0; j < q; j++)
        {
            y[i][j] = 0;
            for (int k = 0; k < n; k++)
                y[i][j] += a[i][k] * b[k][j];
        }
    return y;
}

void GetMatr(int **mas, int **p, int i, int j, int m) {
    int ki, kj, di, dj;
    di = 0;
    for (ki = 0; ki<m - 1; ki++) {
        if (ki == i) di = 1;
        dj = 0;
        for (kj = 0; kj<m - 1; kj++) {
            if (kj == j) dj = 1;
            p[ki][kj] = mas[ki + di][kj + dj];
        }
    }
}

int Determinant(int **mas, int m) {
    int j, d, k, n;
    int **p = create(m);
    j = 0; d = 0;
    k = 1;
    n = m - 1;
    if (m<1) cout << "ERROR";
    if (m == 1) {
        d = mas[0][0];
        return(d);
    }
    if (m == 2) {
        d = mas[0][0] * mas[1][1]-(mas[1][0] * mas[0][1]);
        return(d);
    }
    if (m>2) {
        for (int i = 0; i<m; i++) {
            GetMatr(mas, p, i, 0, m);
            d = d + k * mas[i][0] * Determinant(p, n);
            k = -k;
        }
    }
    return(d);
}

void glav_diag(int **a, int n) {
    for (int i = 0; i < n; i++)
        cout << a[i][i] << ' ';
    cout << endl;
}

void poboch_diag(int **a, int n) {
    for (int i = 0; i < n; i++)
        cout << a[i][n-1-i]<< ' ';
    cout << endl;
}

int main()
{
    ifstream in1("in1.txt");
    ifstream in2("in2.txt");
    ifstream in3("in3.txt");
    if (!in1 || !in2)
    {
        cout << "Can`t open file!" << endl;
        exit(-1);
    }

    int n,m,q,k;
    cout << "Enter size of array a: "; cin >> n >> m;
    cout << "Enter size of array b: "; cin >> m >> q;
    cout << "Enter size of square array g: "; cin >> k;
    int **a, **b,**c,**g;
    a = create_mass(in1, n, m);
    b = create_mass(in2, m, q);
    g = create_mass(in3, k, k);
    c = summ(g, g, k);

    cout << "A: " << endl;
    table(a, n, m);
    cout << "B: " << endl;
    table(b, m, q);
    cout << "G: " << endl;
    table(g, k, k);
    cout << "Sum:" << endl;
    table(c, k, k);
    cout << "Mult: " << endl;
    table(mult(a, b, m, n, q),m+1,m+1);
    cout << "Diag: "; glav_diag(g, k);
    cout << "Pob diag: "; poboch_diag(g, k);
    cout << "Determinant: " << Determinant(g, k)<<endl;
    cout << "Transp: " << endl;
    table(transp(g, k), k, k);

    in1.close();
    in2.close();
    system("pause");
}