Cod sursa(job #2743119)

Utilizator levladiatorDragutoiu Vlad-Ioan levladiator Data 22 aprilie 2021 16:24:04
Problema Algoritmul lui Gauss Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.84 kb

#include <bits/stdc++.h>

using namespace std;
ifstream fin("gauss.in");
ofstream fout("gauss.out");


const double EPS=1e-10;
const int NMAX=305;

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

void gauss()
{
    int i=1,j=1,k,p;
    while(i<=N&&j<=M)
    {
        if(abs(A[i][j])<=EPS)
        {
            bool ok=0;
            for(k=i+1;k<=N;k++)
            {
                if(abs(A[k][j])>EPS)
                {
                    ok=1;
                    for(p=j;p<=M+1;p++)
                    {
                        swap(A[i][p],A[k][p]);
                    }
                    break;
                }
            }
            if(ok==0)
            {
                j++;
                continue;
            }
        }
        for(k=j+1;k<=M;k++)
        {
            A[i][k]/=A[i][j];
        }
        A[i][j]=1.0;
        for(k=i+1;k<=N;k++)
        {
            for(p=j+1;p<=M+1;p++)
            {
                A[k][p]-=A[k][j]*A[i][p];
            }
            A[k][j]=0.0;
        }
        i++;
        j++;
    }
}

int solutie()
{
    for(int i=N;i>=1;i--)
    {
        for(int j=i;j<=M+1;j++)
        {
            if(abs(A[i][j])>EPS)
            {
                if(j==M+1)return 0;
                X[j]=A[i][M+1];
                for(int k=j+1;k<=M;k++)
                    X[j]-=X[k]*A[i][k];
                break;
            }
        }
    }
    return 1;
}

void afisare()
{
    fout.setf(ios::fixed,ios::floatfield);
    fout.precision(10);
    for(int i=1;i<=M;i++)
    {
        fout<<X[i]<<' ';
    }
}

int main()
{
    fin>>N>>M;
    for(int i=1;i<=N;i++)
    {
        for(int j=1;j<=M;j++)
        {
            fin>>A[i][j];
        }
    }
    gauss();

    if(solutie())afisare();
    else fout<<"Imposibil";

    return 0;
}