Cod sursa(job #2951048)

Utilizator IvanAndreiIvan Andrei IvanAndrei Data 5 decembrie 2022 10:21:24
Problema Algoritmul lui Gauss Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.99 kb
#include <fstream>
#include <vector>
#include <iomanip>

using namespace std;

ifstream in ("gauss.in");
ofstream out ("gauss.out");

const double eps = 1e-8;

vector <vector <double>> sis;
double ans[100001];

int main ()
{
    int n, m;
    in >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        vector <double> v;
        double x;
        for (int j = 1; j <= m + 1; j++)
        {
            in >> x;
            v.push_back(x);
        }
        sis.push_back(v);
    }
    int i = 0, j = 0;
    while (i < n && j < m)
    {
        int k;
        for (k = i; k < n; k++)
        {
            if (sis[k][j] < -eps || sis[k][j] > eps)
            {
                break;
            }
        }
        if (k == n)
        {
            j++;
            continue;
        }
        if (i != k)
        {
            swap(sis[i], sis[k]);
        }
        for (int p = j + 1; p <= m; p++)
        {
            sis[i][p] /= sis[i][j];
        }
        sis[i][j] = 1;
        for (int p = i + 1; p < n; p++)
        {
            for (int q = j + 1; q <= m; q++)
            {
                sis[p][q] -= sis[p][j] * sis[i][q];
            }
            sis[p][j] = 0;
        }
        i++;
        j++;
    }
    for (i = n - 1; i >= 0; i--)
    {
        for (j = 0; j <= m; j++)
        {
            if (sis[i][j] < -eps || sis[i][j] > eps)
            {
                if (j == m)
                {
                    out << "Imposibil";
                    in.close();
                    out.close();
                    return 0;
                }
                else
                {
                    ans[j] = sis[i][m];
                    for (int k = j + 1; k < m; k++)
                    {
                        ans[j] -= ans[k] * sis[i][k];
                    }
                    break;
                }
            }
        }
    }
    out << fixed << setprecision(10);
    for (i = 0; i < m; i++)
    {
        out << ans[i] << " ";
    }
    in.close();
    out.close();
    return 0;
}