math4

#include <iostream>

using namespace std;

double* solveMatrix (int n, double *bot, double *mid, double *top, double *d)
{
	double* P = new double[n];
	double* Q = new double[n];
	double* res = new double[n];

	P[0] = -top[0] / mid[0];
	Q[0] = d[0] / mid[0];

	for (int i = 1; i < n; i++)
	{
		P[i] = -top[i] / (mid[i] + bot[i] * P[i-1]);
		Q[i] = (d[i] - bot[i] * Q[i-1]) / (mid[i] + bot[i] * P[i-1]);
	}

	res[n-1] = Q[n-1];

	for (int i = n - 2; i >= 0; i--)
		res[i] = P[i] * res[i+1] + Q[i];

	return res;
}

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

	int n;
	cout << "Количество переменных:" << endl;
	cin >> n;
	cout << endl;

	double** mat = new double*[n];
	double* matRes = new double[n];

	for (int i = 0; i < n; i++)
		mat[i] = new double[n+1];

	for (int i = 0; i < n; i++)
		for (int j = 0; j < n + 1; j++)
			mat[i][j] = 0;


	cout << "Введите СЛАУ:" << endl;

	for (int i = 0; i < n; i++)
	{
		cout << "Строка " << i + 1 << ": " << endl;
		if (i > 0)
			cin >> mat[i][i-1];

		cin >> mat[i][i];

		if (i < n - 1)
			cin >> mat[i][i+1];

		cin >> mat[i][n];
	}

	cout << endl;

	double* diagTop = new double[n];
	double* diag = new double[n];
	double* diagBot = new double[n];
	double* rightPath = new double[n];

	diagTop[n - 1] = 0;
	for (int i = 0; i < n - 1; i++)
		diagTop[i] = mat[i][i+1];

	for (int i = 0; i < n; i++)
		diag[i] = mat[i][i];

	diagBot[0] = 0;
	for (int i = 1; i < n; i++)
		diagBot[i] = mat[i][i-1];

	for (int i = 0; i < n; i++)
		rightPath[i] = mat[i][n];

	double* res = solveMatrix(n, diagBot, diag, diagTop, rightPath);

	cout << "Результат" << endl;

	for (int i = 0; i < n; i++)
		cout << res[i] << endl;

	system("pause");
	return 0;
}