ricxviti lab 4

#include <iostream>
#include <vector>
#include <fstream>
#include <cmath>

using namespace std;

const int n(3);

double getNorm(const vector<double> &);
void printV(const vector<double> &);

int main() {
    vector<double> z(n), q(n);
    vector<vector<double>> A(n, n);
    double norm(0), la_old, la_new(1), eps(0.000001);
    ifstream ifs("data.dat");
    //
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            ifs >> A[i][j];
    for (int i = 0; i < n; i++)
        ifs >> z[i];
    // sawyisi miaxloebis gamotvla
    norm = getNorm(z);
    for (int i = 0; i < n; i++)
        q[i] = z[i] / norm;
    //
    for (int i = 0; i < n; i++) {
        z[i] = 0;
        for (int j = 0; j < n; j++)
            z[i] += A[i][j] * q[j];
    }
    //
    int k(0), k_max(500);
    do {
        k++;
        la_old = la_new;
        norm = getNorm(z);
        for (int i = 0; i < n; i++)
            q[i] = z[i] / norm;
        for (int i = 0; i < n; i++) {
            z[i] = 0;
            for (int j = 0; j < n; j++)
                z[i] += A[i][j] * q[j];
        }
        la_new = 0;
        for (int i = 0; i < n; i++)
            la_new += z[i] * q[i];
    } while (fabs(la_new - la_old) > eps && k < k_max);
    cout << "k = " << k << endl;
    cout << "modulit udidesi sakutrivi ricxvi = " << la_new << endl;
    printV(q);
    return(0);
}

double getNorm(const vector<double> & v) {
    double norm(0);
    for (int i = 0; i < n; i++)
        norm += v[i] * v[i];
    return sqrt(norm);
}

void printV(const vector<double> & v) {
    for (int i = 0; i < n; i++)
        cout << v[i] << " ";
    cout << endl;
}