main.cpp

#include <iostream>
#include <vector>
#include <fstream>
#include <chrono>
#include <iomanip>

#ifdef _OPENMP
#include <omp.h>
#endif

using namespace std;

bool readMatrix(const string& filename, vector<double>& matrix, int& n) {
    ifstream in(filename);
    if (!in.is_open()) return false;

    in >> n;
    matrix.resize(n * n);
    for (int i = 0; i < n * n; ++i) {
        in >> matrix[i];
    }
    return true;
}

void saveMatrix(const string& filename, const vector<double>& matrix, int n) {
    ofstream out(filename);
    out << n << endl;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            out << fixed << setprecision(6) << matrix[i * n + j] << " ";
        }
        out << endl;
    }
}

int main(int argc, char* argv[]) {
    if (argc < 4) {
        cout << "Usage: " << argv[0] << " <input1> <input2> <output> [threads]" << endl;
        return 1;
    }

    string fileA = argv[1];
    string fileB = argv[2];
    string fileRes = argv[3];
    int numThreads = (argc > 4) ? stoi(argv[4]) : 1;

    int n1, n2;
    vector<double> A, B;

    if (!readMatrix(fileA, A, n1) || !readMatrix(fileB, B, n2)) {
        cerr << "Error reading input files!" << endl;
        return 1;
    }

    if (n1 != n2) {
        cerr << "Matrices must be of the same size!" << endl;
        return 1;
    }

    int n = n1;
    vector<double> C(n * n, 0.0);

    // Установка количества потоков
#ifdef _OPENMP
    omp_set_num_threads(numThreads);
#endif

    auto start = chrono::high_resolution_clock::now();

    // Перемножение матриц
    #pragma omp parallel for collapse(2)
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            double sum = 0;
            for (int k = 0; k < n; ++k) {
                sum += A[i * n + k] * B[k * n + j];
            }
            C[i * n + j] = sum;
        }
    }

    auto end = chrono::high_resolution_clock::now();
    chrono::duration<double> diff = end - start;

    saveMatrix(fileRes, C, n);

    cout << "Task size (N): " << n << endl;
    cout << "Threads: " << numThreads << endl;
    cout << "Execution time: " << diff.count() << " seconds" << endl;

    return 0;
}