Prostie iteracii

#include "pch.h"
#include <iostream>


using namespace std;
int main()
{
    setlocale(LC_ALL, "Russian");
    double ebs;
    int n;
    double arr[100][100];
    cout << "Введите размер матрицы" << endl;
    cin >> n;
    cout << "Введите матрицу" << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j <= n; j++) {
            cin >> arr[i][j];
        }
    }
    cout << "Введите максимальную погрешность " << endl;
    cin >> ebs;
    for (int i = 0; i < n; i++) {

        int pos = 0;
        for (int j = 0; j < n; j++) {
            if (arr[pos][i] < arr[j][i]) {
                pos = j;
            }
        }
        double z[100];
        for (int j = 0; j <= n; j++) {
            z[j] = arr[i][j];
            arr[i][j] = arr[pos][j];
            arr[pos][j] = z[j];
        }
    }
    cout << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j <= n; j++) {
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }

    double x[100];
    double xxx[100];
    bool z;
    int k = 0;
    for (int i = 0; i < n; i++) xxx[i] = 0;
    do{
        k++;
        z = false;
        for (int i = 0; i < n; i++) {
            x[i] = arr[i][n];

            for (int j = 0; j < n; j++) {
                if (j != i) {
                    x[i] -= arr[i][j] * xxx[j];
                }
            }
            x[i] /= arr[i][i];
            if (fabs(xxx[i] - x[i]) > ebs) {
                z = true;
            }
        }
        for (int j = 0; j < n; j++) {
            xxx[j] = x[j];
        }
    } while (z);
    for (int j = 0; j < n; j++) {
        cout <<"x"<<j+1<<" = "<< xxx[j] << endl;
    }
    cout << "Количество итераций " << k;

    return 0;
}