VP_3_VRASHENIYA

http://algorithmlib.org/rotation_slay


#include <iomanip>
#include<iostream>
#include <math.h>
#include <vector>

using namespace std;

void prnt(vector<vector<double>> &matrix){
    int i, j;
    for (i = 0; i < matrix.size(); i++){
        for (j = 0; j < matrix[i].size(); j++){
            cout << matrix[i][j] << fixed << setprecision(8)<< "  ";
        }
        cout << "\n";
    }
    cout << "\n";
}

void TUDA_SUDA(vector<vector<double>>&A, vector<double>&otv){// метод вращения
    int n = A.size();
    int count = 0;
    for (int k = 0; k < n; k++){
        for (int i = k + 1; i < n; i++){
            double cos = A[k][k] / sqrt(A[k][k] * A[k][k] + A[i][k] * A[i][k]);    //sqr(cos) + sqr(sin) = 1;
            double sin = A[i][k] / sqrt(A[k][k] * A[k][k] + A[i][k] * A[i][k]);    //
            for (int j = k; j <= n; j++){
                double prm = cos*A[k][j] + sin*A[i][j];
                A[i][j] = -sin*A[k][j] + cos*A[i][j];
                A[k][j] = prm;
                prnt(A);
            }
            cout << "Q " << count++ << " A\n";
            prnt(A);
        }
    }

    //Обратный ход:
    otv[n - 1] = A[n - 1][n] / A[n - 1][n - 1];
    A[n - 1][n] = otv[n - 1];
    for (int i = n - 2; i >= 0; i--){
        for (int j = i + 1; j < n; j++)
        {
            otv[i] = A[i][n] - otv[j] * A[i][j];
            A[i][n] = otv[i];
        }
        otv[i] /= A[i][i];
    }
}


int main(){
    setlocale(LC_ALL, "rus");

    int n, m;
    cout << "размерность: ";
    cin >> n;
    m = n + 1;

    vector<vector<double>> Ab(n, vector<double>(m));
    /*Ab[0] = { -93.6, 23.8, 13.7, 10 };
    Ab[1] = { 11.14, 23.18, 41.3, 15.9 };
    Ab[2] = { 13, 15.3, 19.3, 32.6 };*/
    //0.686098 4.43678 -2.29026

    for (int i = 0; i < Ab.size (); i++){
    for (int j = 0; j < Ab[i].size (); j++){
    cin >> Ab[i][j];
    }
    cout<<endl;
    }

    cout << "Начальная матрица.\n";
    prnt(Ab);
    system("pause");

    vector<double> X(n);
    TUDA_SUDA(Ab, X);

    cout << "Результат:\n";
    for (int i = 0; i < n; i++){
        cout << "x" << i + 1 << "=" << X[i] << endl;
    }

    system("pause");

    return 0;
}