th.cpp

#include "stdafx.h"
#include <iostream>
#include <string>
#include <iomanip>
#include <cmath>
#include <conio.h>
#include <ctime>

using namespace std;
void printMatrix(double *tab, size_t rows, string name) {
	cout << "----------------" << endl;
	for (size_t i = 0; i < rows; i++)
	{
		std::cout << name << i << "=" << tab[i] << endl;
	}
	cout << "----------------" << endl;
}
void printDiagonal(double **tab, size_t rows) {
	for (size_t i = 0; i < rows; i++)
	{
		for (size_t e = 0; e < 3; e++) {
			std::cout << "" << tab[i][e] << "\t";
		}
		std::cout << endl;
	}
}
int main()
{
	srand(time(nullptr));
	double **A, *W, *X;
	int i,n;
	cout << "Podaj liczbe rownan" << endl;
	cin >> n;
	A = new double *[n];
	W = new double[n];
	X = new double[n];
	double *beta = new double[n];
	double *gamma = new double[n];
	for (i = 0; i < n; i++) {
		A[i] = new double[3];
	}
	for (size_t i = 0; i < n; i++)
	{
		W[i] = 3;
	}
	if (n == 5) {
		A[0][0] = 0;
		A[0][1] = 2;
		A[0][2] = 2;

		A[1][0] = 3;
		A[1][1] = 1;
		A[1][2] = 1;

		A[2][0] = 1;
		A[2][1] = 2;
		A[2][2] = 4;

		A[3][0] = 1;
		A[3][1] = 1;
		A[3][2] = 1;

		A[4][0] = 2;
		A[4][1] = 2;
		A[4][2] = 0;

		W[0] = 2;
		W[1] = 6;
		W[2] = 4;
		W[3] = 1;
		W[4] = 4;
	}
	else {
		double insert;
		for (size_t i = 0; i < n; i++)
		{
			for (size_t j = 0; j < 3; j++)
			{
				cout << "podaj element o wspolrzednych: " << i << "," << j << endl;
				cin >> insert;
				A[i][j] = insert;
			}
		}
		for (size_t i = 0; i < n; i++)
		{
			cout << "podaj wynik o wspolrzednych: " << i << endl;
			cin >> insert;
			W[i] = insert;
		}
	}
	printDiagonal(A, n);
	printMatrix(W, n, "wyniki");

	//ustawiamy pierwszy i ostatni element przekatnej na 0
	A[0][0] = 0; //a1 = 0
	A[n-1][2] = 0; //cn = 0
	//obliczamy startowe beta i gamma
	beta[0] = -(A[0][2]/A[0][1]);
	gamma[0] = W[0]/A[0][1];
	//obliczamy beta i gamma od "przodu"
	for (size_t i = 1; i < n; i++)
	{
		beta[i] = -(A[i][2]/(A[i][0]*beta[i-1]+A[i][1]));
		gamma[i] = (W[i] - A[i][0] * gamma[i - 1]) / ((A[i][0] * beta[i - 1]) + A[i][1]);
	}
	printMatrix(beta, n, "beta");
	printMatrix(gamma, n, "gamma");
	//obliczamy x od "tylu"
	X[n] = gamma[n];
	for (int i = n; i>=0; i--)
	{
		X[i] = beta[i] * X[i+1] + gamma[i];
//		cout << X[i];
	}
	printMatrix(X, n, "X");
	return 0;
}