Gayss_01

#include <math.h>
#include <iostream.h>
#include <stdio.h>

int main()
{

    double A[101][101];
    double B[101][1];
    double X[101][1];
    double koeff, koeff2, temp1, temp2, temp3, temp4;
    int size, num=0;

//-------------------------------------------------|

    cout<<"Vvedite razmer matricsi sistemi: ";
    cin>>size;

    cout<<"Vvedite element matricsi A: "<<endl;
    for ( int a1=0; a1<size; a1++)
    {
        for ( int a2=0; a2<size; a2++)
        {
            cin>>A[a1][a2];
        }
    }

    cout<<"Vvedennaya matricsa: "<<endl;
    for ( int a3=0; a3<size; a3++)
    {
        for ( int a4=0; a4<size; a4++)
        {
            cout<<A[a3][a4]<<" ";
        }
        cout<<endl;
    }
//-------------------------------------------------|

    cout<<"Vvedite stolbecs svobodnich chlenov: ";
    for ( int b1=0; b1<size; b1++)
    {
        cin>>B[b1][0];
    }

    cout<<"Vvedennii stolbecs svobodnich chlenov: "<<endl;
    for ( int b2=0; b2<size; b2++)
    {
        cout<<B[b2][0]<<endl;
    }

//-------------------------------------------------|

    double max=0;
    for ( int c1=0; c1<size; c1++)
    {
        if ( fabs(A[c1][0])>max)
        {
            max=A[c1][0];
            num=c1;
        }
    }

    cout<<max<<" "<<num+1<<endl;

//-------------------------------------------------|

    for ( int d1=0; d1<size; d1++)
    {
        temp1=A[0][d1];
        A[0][d1]=A[num][d1];
        A[num][d1]=temp1;
    }

    temp2=B[0][0];
    B[0][0]=B[num][0];
    B[num][0]=temp2;

    cout<<"Vvedennaya matricsa: "<<endl;
    for ( int d2=0; d2<size; d2++)
    {
        for ( int d3=0; d3<size; d3++)
        {
            cout<<A[d2][d3]<<" ";
        }
        cout<<endl;
    }

    for ( int d4=0; d4<size; d4++)
    {
        cout<<B[d4][0]<<endl;
    }

//-------------------------------------------------|

    for ( int e1=0; e1<size; e1++)
    {
        for ( int e2=e1; e2<size-1; e2++)
        {
            koeff=A[e2+1][e1]/A[e1][e1];
            B[e2+1][0]=B[e2+1][0]-B[e1][0]*koeff;
            for ( int e3=e1; e3<size; e3++)
            {
                A[e2+1][e3]=A[e2+1][e3]-A[e1][e3]*koeff;
            }
        }
    }

    cout<<"Vvedennaya matricsa: "<<endl;
    for ( int e4=0; e4<size; e4++)
    {
        for ( int e5=0; e5<size; e5++)
        {
            cout<<A[e4][e5]<<" ";
        }
        cout<<endl;
    }

    for ( int e6=0; e6<size; e6++)
    {
        cout<<B[e6][0]<<endl;
    }

//-------------------------------------------------|
/*
    for ( int f1=size; f1>0; f1--)
    {
        for ( int f2=f1; f2>0+1; f2--)
        {
            koeff=A[f2-1][f1]/A[f1][f1];
            B[f2-1][0]=B[f2-1][0]-B[f1][0]*koeff;
            for ( int f3=f1; f3>0; f3--)
            {
                A[f2-1][f3]=A[f2-1][f3]-A[f1][f3]*koeff;
            }
        }
    }

    cout<<"Vvedennaya matricsa: "<<endl;
    for ( int f4=0; f4<size; f4++)
    {
        for ( int f5=0; f5<size; f5++)
        {
            cout<<A[f4][f5]<<" ";
        }
        cout<<endl;
    }

    for ( int f6=0; f6<size; f6++)
    {
        cout<<B[f6][0]<<endl;
    }
*/
//-------------------------------------------------|

    for ( int f1=size; f1>0; f1--)
    {
        for ( int f2=f1; f2>0; f2--)
        {
            koeff2=A[f2-1][f1]/A[f1][f1];
            B[f2-1][0]=B[f2-1][0]-B[f1][0]*koeff2;
            for ( int f3=f1; f3>0; f3--)
            {
                A[f2-1][f3]=A[f2-1][f3]-A[f1][f3]*koeff;
            }
        }
    }

    cout<<"Vvedennaya matricsa: "<<endl;
    for ( int f4=0; f4<size; f4++)
    {
        for ( int f5=0; f5<size; f5++)
        {
            cout<<A[f4][f5]<<" ";
        }
        cout<<endl;
    }

    for ( int f6=0; f6<size; f6++)
    {
        cout<<B[f6][0]<<endl;
    }

//-------------------------------------------------|
/*
for(r=1;r<n;r++)
    {
        for(i=1;i<=r;i++)
        {
            t=mas[i-1][r]/mas[r][r];
            B[i-1]=B[i-1]-B[r]*t;
            for(j=r;j<n;j++)
            {
                mas[i-1][j]=mas[i-1][j]-mas[r][j]*t;
            }
        }
    }
*/

    return 0;
}