main

#include <iostream>
#include <fstream>
#include <cmath>
#include <cstring>
#include <chrono>
#include <cstdlib>

void initializeMatrix(int s, int n, double *A, const char *filename);
void computeVectorB(int n, double *A, double *b);
int gauss(int n, double *A, double *b, double *x);
void printMatrix(int l, int n, double *A, int r);
void computeResiduals(int n, double *A, double *b, double *x, double &r1, double &r2);

int main(int argc, char *argv[]) {
    if (argc < 4) {
        std::cerr << "Usage: " << argv[0] << " n r s [filename]" << std::endl;
        return 1;
    }

    int n = std::atoi(argv[1]);
    int r = std::atoi(argv[2]);
    int s = std::atoi(argv[3]);
    const char *filename = (s == 0 && argc > 4) ? argv[4] : nullptr;

    double *A = new double[n * n];
    double *b = new double[n];
    double *x = new double[n];

    initializeMatrix(s, n, A, filename);
    computeVectorB(n, A, b);

    std::cout << "Initial matrix A:" << std::endl;
    printMatrix(n, n, A, r);

    auto start = std::chrono::high_resolution_clock::now();
    int result = gauss(n, A, b, x);
    auto end = std::chrono::high_resolution_clock::now();
    double t1 = std::chrono::duration<double>(end - start).count();

    double r1 = -1.0;
    double r2 = -1.0;
    double t2 = 0.0;

    if (result == 0) {
        initializeMatrix(s, n, A, filename);
        computeVectorB(n, A, b);
        start = std::chrono::high_resolution_clock::now();
        computeResiduals(n, A, b, x, r1, r2);
        end = std::chrono::high_resolution_clock::now();
        t2 = std::chrono::duration<double>(end - start).count();

        std::cout << "Solution x:" << std::endl;
        printMatrix(1, n, x, r);
    }

    printf("%s : Task = %d Res1 = %e Res2 = %e T1 = %.2f T2 = %.2f S = %d N = %d\n",
           argv[0], 1, r1, r2, t1, t2, s, n);

    delete[] A;
    delete[] b;
    delete[] x;

    return 0;
}