Cod sursa(job #1610470)

Utilizator ArkinyStoica Alex Arkiny Data 23 februarie 2016 16:09:46
Problema Algoritmul lui Gauss Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
#include<fstream>
#include<algorithm>
using namespace std;
ifstream in("gauss.in");
ofstream out("gauss.out");

double A[310][310];
double var[310];
int N, M;

void swap_lines(int l1, int l2)
{
	for (int i = 1; i <= M + 1; ++i)
		swap(A[l1][i], A[l2][i]);
}

int main()
{
	int N, M;
	in >> N >> M;
	for (int i = 1; i <= N; ++i)
		for (int j = 1; j <= M + 1; ++j)
			in >> A[i][j];
    
	for (int j = 1; j <= M; ++j)
	{
		int p = -1;
		for (int i = j; i <= N; ++i)
			if (A[i][j] != 0)
			{
				p = i;
				break;
			}
		if (p != -1)
		{
			swap_lines(p, j);
			for (int i = j + 1; i <= N; ++i)
					for (int k = j + 1; k <= M + 1; ++k)
						A[i][k] -= (A[i][j] * A[j][k]) / A[j][j];
			for (int i = j + 1; i <= N; ++i)
				A[i][j] = 0;
		}
	}

	var[M] = A[M][M + 1] / A[M][M];
	for (int i = M - 1; i >= 1; --i)
	{
		var[i] = A[i][M + 1];
		for (int j = M; j > i; --j)
			var[i] -= A[i][j] * var[j];
		if (var[i] != 0 && A[i][i] == 0)
		{
			out << "Imposibil";
			return 0;
		}
		var[i] = var[i] / A[i][i];
	}

	for (int i = 1; i <= M; ++i)
		out << var[i] << " ";


	return 0;
}