Cod sursa(job #1937184)

Utilizator darian2001Clodnischi Darian Antonio darian2001 Data 23 martie 2017 19:30:24
Problema Algoritmul lui Gauss Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.7 kb
#include <fstream>
using namespace std;

#define EPS 0.0000001
#define Nmax 310

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

int n,m;
double A[Nmax][Nmax];
double X[Nmax];

void citire()
{
    f>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m+1;j++)
            f>>A[i][j];
}

void afisare()
{
    for(int i=1;i<=m;i++)
        g<<X[i]<<'\n';
}

void gauss_alg()
{
    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][j];
        A[i][j]=1;

        for(int u=i+1;u<=n;++u)
        {
            if(A[u][j]<-EPS||A[u][j]>EPS)
                for(int l=j+1;l<=m+1;++l)
                    A[u][l]-=A[u][j]*A[i][l];
            A[u][j]=0;
        }
        ++i;++j;
    }
}

int gasire_necunoscute()
{
    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)
                {
                    g<<"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;
            }
    afisare();
}



int main()
{
    citire();
    gauss_alg();
    gasire_necunoscute();

    f.close();
    g.close();
}