Cod sursa(job #3343658)

Utilizator alexdraguAlexandru Dragu alexdragu Data 28 februarie 2026 09:12:55
Problema Algoritmul lui Gauss Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.67 kb
#include <fstream>
#include <cmath>
#include <iomanip>
#define error 1e-3
using namespace std;
ifstream cin("gauss.in");
ofstream cout("gauss.out");
int n,m,i,j,where[305];
double a[305][305],sol[305],b[305][305];
bool gauss()
{
    int i,j;
    for(j=1; j<=m; j++)
    {
        sol[j]=0;
        where[j]=0;
    }
    for(i=1,j=1; i<=n&&j<=m; j++)
    {
        int rand=i;
        double val=fabs(a[i][j]);
        for(int row=i; row<=n; row++)
        {
            if(fabs(val)<fabs(a[row][j]))
            {
                rand=row;
                val=fabs(a[row][j]);
            }
        }
        if(val<error) continue;
        where[j]=i;
        for(int col=j; col<=m+1; col++)
            swap(a[i],a[rand]);
        for(int row=1; row<=n; row++)
        {
            if(row!=i)
            {
                double c=a[row][j]/a[i][j];
                for(int col=j; col<=m+1; col++)
                    a[row][col]-=c*a[i][col];
            }
        }
        i++;
    }

    for(j=1;j<=m;j++)
    {
        if(where[j]!=0)
        {
            sol[j]=a[where[j]][m+1]/a[where[j]][j];
        }
    }
    for(i=1;i<=n;i++)
    {
        int sum=0;
        for(j=1;j<=m;j++)
            sum+=sol[j]*b[i][j];
        sum-=b[i][m+1];
        if(fabs(sum)>error) return false;
    }
    return true;
}
int main()
{
    cin>>n>>m;
    for(i=1; i<=n; i++)
    {
        for(j=1; j<=m+1; j++)
        {
            cin>>a[i][j];
            b[i][j]=a[i][j];
        }
    }
    if(gauss())
    {
        for(i=1; i<=m; i++) cout<<fixed<<setprecision(10)<<sol[i]<<' ';
    }
    else cout<<"Imposibil";
    return 0;
}