Cod sursa(job #903083)

Utilizator nosurrender99Bura Bogdan nosurrender99 Data 1 martie 2013 18:26:18
Problema Algoritmul lui Gauss Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 2.09 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,int);
void schimba(int,int);
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,j=1;i<=n && j<=m;j++,i++)
    {
        if (a[i][j]==0)
            cauta(i,j);
        if(a[i][j]!=0)
        {
            for(int k=j+1;k<=m+1;k++)
                a[i][k]/=a[i][j];
            a[i][j]=1;
            for(int l=i+1;l<=n;l++)
            {
                for(int k=j+1;k<=m+1;k++)
                    a[l][k]=a[l][k]-a[i][k]*a[l][j];
                a[l][j]=0;
            }
        }
        else
            i--;
    }
      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 x,int y)
{
    int i=x+1;
    while(a[i][y]==0 && i<=n)
        i++;
    if (i<=n)
        schimba(x,i);
}

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

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;

}