Cod sursa(job #902892)

Utilizator nosurrender99Bura Bogdan nosurrender99 Data 1 martie 2013 17:15:53
Problema Algoritmul lui Gauss Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.96 kb
#include <fstream>
#include <iomanip>
#include <cstdlib>
using namespace std;
#define EPS 0.0000001

fstream f("gauss.in", ios::in), g("gauss.out", ios::out);

float a[303][303],X[303];
int m,n;
void solve();
void cauta(int);
void schimba(int,int);
void redu(int,int,float);
void imparte(int,float);
bool nonz ();

int main()
{
    f>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m+1;j++)
            f>>a[i][j];
    solve();
    for(int i=1;i<=m;i++)
    {
        g<<fixed<<setprecision (8)<<X[i]<<" ";
    }
    return 0;
}

void solve()
{
    for(int i=1;i<=m;i++)
    {
        if (a[i][i]==0)
            cauta(i);
        imparte(i,a[i][i]);
        for(int j=i+1;j<=n;j++)
        {
            float d=a[j][i];
            redu(i,j,d);
        }
    }
      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"<<endl;
                    exit(0);
                }
                X[j] = a[i][m+1];
                for(int k = j+1; k <= m; ++k)
                    X[j] -= X[k] * a[i][k];

                break;
            }


}

void cauta(int m)
{
    int i=m+1;
    while(a[i][m]==0 && i<=n)
        i++;
    schimba(m,i);
}

void schimba(int m,int i)
{
    int aux;
    for(int j=1;j<=m+1;j++)
    {
        aux=a[m][j];
        a[m][j]=a[i][j];
        a[i][j]=aux;
    }
}

void redu(int i, int j, float d)
{
    for(int k=i;k<=m+1;k++)
    {
        a[j][k]=a[j][k]-a[i][k]*d;
    }
}

void imparte(int i, float d)
{
    for(int k=i;k<=m+1;k++)
        a[i][k]/=d;
}

bool nonz()
{
    bool bo=true;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m && bo==true;j++)
            if (a[i][j]!=0)
                bo=false;
        if (bo==true && a[i][(int)m+1]!=0)
            return false;
    }
    return true;

}