Crout A=L * U

// Example program
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
int main()
{
    float a[3][3], l[3][3], u[3][3], b[3];
    int i, j;
    for (i = 0;i<3;i++)
        for (j = 0;j<3;j++)
            cin >> a[i][j];
    for (i = 0;i<3;i++) {
        u[i][i] = 1;
    }
    l[0][1] = 0;
    l[0][2] = 0;
    l[1][2] = 0;
    u[1][0] = 0;
    u[2][0] = 0;
    u[2][1] = 0;
    u[1][0] = 0;
    l[0][0] = a[0][0];
    l[1][0] = a[1][0];
    l[2][0] = a[2][0];
    u[0][1] = a[0][1] / l[0][0];
    l[1][1] = a[1][1] - (l[1][0] * u[0][1]);
    l[2][1] = a[2][1] - (l[2][0] * u[0][1]);
    u[0][2] = a[0][2] / l[0][0];
    u[1][2] = (a[1][2] - (l[1][0] * u[0][2]) )/ l[1][1];
    l[2][2] = a[2][2] - (l[2][0] * u[0][2]) -( l[2][1] * u[1][2]);
    for (i = 0;i<3;i++) {
        for (j = 0;j<3;j++)
            cout << l[i][j] << "   ";
        cout << endl;
    }
    cout << "\n==============================\n";
    for (i = 0;i<3;i++) {
        for (j = 0;j<3;j++)
            cout << u[i][j] << "   ";
        cout << endl;
    }
}