Cod sursa(job #608001)

Utilizator GavrilaVladGavrila Vlad GavrilaVlad Data 14 august 2011 15:17:37
Problema Algoritmul lui Gauss Scor Ascuns
Compilator cpp Status done
Runda Marime 1.59 kb
#include <cstdio>

using namespace std;

#define MAXN 310
#define EPS 0.0000001

int N, M;
double A[MAXN][MAXN];
double X[MAXN];

int main()
{
    freopen("gauss.in", "r", stdin);
    freopen("gauss.out", "w", stdout);

    scanf("%d%d", &N, &M);
    for(int i = 1; i <= N; ++i)
        for(int j = 1; j <= M+1; ++j)
            scanf("%lf", &A[i][j]);

    int i = 1, j = 1, k;
    double aux;

    while(i <= N && j <= M)
    {
        for(k = i; k <= N; ++k)
            if(A[k][j]<-EPS || A[k][j]>EPS)
                break;

        if(k == N+1)
        {
            ++j;
            continue;
        }

        if(k != i)
            for(int l = 1; l <= M+1; ++l)
            {
                aux = A[i][l];
                A[i][l] = A[k][l];
                A[k][l] = aux;
            }

        for(int l = j+1; l <= M+1; ++l)
            A[i][l] = A[i][l] / A[i][j];
        A[i][j] = 1;

        for(int u = i+1; u <= N; ++u)
        {
            for(int l = j+1; l <= M+1; ++l)
                A[u][l] -= A[u][j] * A[i][l];
            A[u][j] = 0;
        }

        ++i; ++j;
    }

    for(int i = N; i>0; --i)
        for(int j = 1; j <= M+1; ++j)
            if(A[i][j]>EPS || A[i][j]<-EPS)
            {
                if(j == M+1)
                {
                    printf("Imposibil\n");
                    return 0;
                }

                X[j] = A[i][M+1];
                for(int k = j+1; k <= M; ++k)
                    X[j] -= X[k] * A[i][k];

                break;
            }

    for(int i = 1; i <= M; ++i)
        printf("%.8lf ", X[i]);
    printf("\n");

    return 0;
}