Cod sursa(job #1171642)

Utilizator tudorv96Tudor Varan tudorv96 Data 15 aprilie 2014 23:51:52
Problema Algoritmul lui Gauss Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.48 kb
#include <fstream>
#include <cstdio>
using namespace std;

ifstream fin ("gauss.in");

const int N = 305;
const double eps = 1e-8;

int n, m;
double a[N][N], sol[N];

#define abs(x) ((x>-x)?(x):(-x))

int main() {
    fin >> m >> n;
    for (int i = 1; i <= m; ++i)
        for (int j = 1; j <= n + 1; ++j)
            fin >> a[i][j];
    int i = 1, j = 1, k;
    while (i <= m && j <= n) {
        for (k = i; k <= m; ++k)
            if (abs (a[k][j]) > eps)
                break;
        if (k == m + 1) {
            j++;
            continue;
        }
        if (k != i)
            for (int p = 1; p <= n + 1; ++p)
                swap (a[k][p], a[i][p]);
        for (int p = j + 1; p <= n + 1; ++p)
            a[i][p] /= a[i][j];
        a[i][j] = 1;
        for (int p = i + 1; p <= m; ++p) {
            for (int q = j + 1; q <= n + 1; ++q)
                a[p][q] -= a[i][q] * a[p][j];
            a[p][j] = 0;
        }
        ++i, ++j;
    }
    freopen ("gauss.out", "w", stdout);
    for (i = m; i; --i)
        for (j = 1; j <= n + 1; ++j)
            if (abs (a[i][j]) > eps) {
                if (j == n + 1) {
                    printf ("Imposibil\n");
                    return 0;
                }
                sol[j] = a[i][n+1];
                for (k = j + 1; k <= n; ++k)
                    sol[j] -= sol[k] * a[i][k];
                break;
            }
    for (int i = 1; i <= n; ++i)
        printf("%.10lf ", sol[i]);
}