laba 2

#include<iostream>

#define SizeArray 3

using namespace std;

double fDet(double flArray[SizeArray][SizeArray])
{
    double lfDet;
    lfDet = flArray[0][0] * flArray[1][1] * flArray[2][2] + flArray[1][0] * flArray[2][1] * flArray[0][2] + flArray[0][1] * flArray[1][2] * flArray[2][0] - flArray[0][2] * flArray[1][1] * flArray[2][0] - flArray[0][0] * flArray[1][2] * flArray[2][1] - flArray[0][1] * flArray[1][0] * flArray[2][2];
    return(lfDet);
}

void fMatr(double flArray[SizeArray][SizeArray],double flBArr[SizeArray], double *flXArr, char chFlag)
{
    double lfTrArr[SizeArray][SizeArray];

    lfTrArr[0][0] = flArray[1][1] * flArray[2][2] - flArray[1][2] * flArray[2][1];
    lfTrArr[1][0] = (flArray[1][0] * flArray[2][2] - flArray[2][0] * flArray[1][2])*(-1);
    lfTrArr[2][0] = flArray[1][0] * flArray[2][1] - flArray[2][0] * flArray[1][1];
    lfTrArr[0][1] = (flArray[0][1] * flArray[2][2] - flArray[2][1] * flArray[0][2])*(-1);
    lfTrArr[1][1] = flArray[0][0] * flArray[2][2] - flArray[2][0] * flArray[0][2];
    lfTrArr[2][1] = (flArray[0][0] * flArray[2][1] - flArray[2][0] * flArray[0][1])*(-1);
    lfTrArr[0][2] = flArray[0][1] * flArray[1][2] - flArray[1][1] * flArray[0][2];
    lfTrArr[1][2] = (flArray[0][0] * flArray[1][2] - flArray[1][0] * flArray[0][2])*(-1);
    lfTrArr[2][2] = flArray[1][1] * flArray[0][0] - flArray[1][0] * flArray[0][1];

    cout.width(-7);
    if (chFlag == 'y')
    {
        cout << "\ndet=" << fDet(flArray) << endl;
            for (int i = 0; i < SizeArray; ++i)
        {
            cout << endl;
            for (int j = 0; j < SizeArray; ++j)
            {
                cout << lfTrArr[i][j]/fDet(flArray) << "\t";
            }
        }
    }

    flXArr[0] = (lfTrArr[0][0] * flBArr[0] + lfTrArr[0][1] * flBArr[1] + lfTrArr[0][2] * flBArr[2]) / fDet(flArray);
    flXArr[1] = (lfTrArr[1][0] * flBArr[0] + lfTrArr[1][1] * flBArr[1] + lfTrArr[1][2] * flBArr[2]) / fDet(flArray);
    flXArr[2] = (lfTrArr[2][0] * flBArr[0] + lfTrArr[2][1] * flBArr[1] + lfTrArr[2][2] * flBArr[2]) / fDet(flArray);
}

void fKram(double flArray[SizeArray][SizeArray], double flBArr[SizeArray], double *flXArr, char chFlag)
{
    double lfTempArr[SizeArray][SizeArray];

    for (int i = 0; i < SizeArray; ++i)
    {
        for (int j = 0; j < SizeArray; ++j)
        {
            lfTempArr[i][j] = flArray[i][j];
        }
    }
    for (int j = 0; j < SizeArray; ++j)
    {
        lfTempArr[j][0] = flBArr[j];
    }
    flXArr[0] = fDet(lfTempArr) / fDet(flArray);
    if (chFlag == 'y')
    {
        cout << "det1=" << fDet(lfTempArr) << endl;
    }

    for (int i = 0; i < SizeArray; ++i)
    {
        for (int j = 0; j < SizeArray; ++j)
        {
            lfTempArr[i][j] = flArray[i][j];
        }
    }
    for (int j = 0; j < SizeArray; ++j)
    {
        lfTempArr[j][1] = flBArr[j];
    }
    flXArr[1] = fDet(lfTempArr) / fDet(flArray);
    if (chFlag == 'y')
    {
        cout << "det2= " << fDet(lfTempArr) << endl;
    }

    for (int i = 0; i < SizeArray; ++i)
    {
        for (int j = 0; j < SizeArray; ++j)
        {
            lfTempArr[i][j] = flArray[i][j];
        }
    }
    for (int j = 0; j < SizeArray; ++j)
    {
        lfTempArr[j][2] = flBArr[j];
    }
    flXArr[2] = fDet(lfTempArr) / fDet(flArray);
    if (chFlag == 'y')
    {
        cout << "det3= " << fDet(lfTempArr) << endl;
    }
}

int main()
{
    double flArray[SizeArray][SizeArray] = { {0.46,1.72,2.53},{1.53,-2.32,-1.83},{0.75,0.86,3.72} }, flBArr[SizeArray] = { 2.44,2.83,1.06 }, flXArr[SizeArray];
    char chFlag;
    cout << "Enter y to output all actions:" << endl;
    chFlag=cin.get();
    fMatr(flArray, flBArr, flXArr, chFlag);
    cout << "\n\nMATRIX method:\n\tx1=" << flXArr[0] << "\n" << "\tx2= " << flXArr[1] << "\n" << "\tx3= " << flXArr[2] << endl;
    cout << "\n\t\t******\n" << endl;
    fKram(flArray, flBArr, flXArr, chFlag);
    cout << "\nKRAMER method:\n\tx1=" << flXArr[0] << "\n" << "\tx2= " << flXArr[1] << "\n" << "\tx3= " << flXArr[2] << endl;

    cin.get();
    cin.get();
}