Assignment

#include<bits/stdc++.h>

using namespace std;

void LUdecomposition(float a[10][10], float l[10][10], float u[10][10], int n)
{

    int i = 0, j = 0, k = 0;

    for (i = 0; i < n; i++)
    {

        for (j = 0; j < n; j++)
        {

            if (j < i)

                l[j][i] = 0;

            else
            {

                l[j][i] = a[j][i];

                for (k = 0; k < i; k++)
                {

                    l[j][i] = l[j][i] - l[j][k] * u[k][i];

                }

            }

        }

        for (j = 0; j < n; j++)
        {

            if (j < i)

                u[i][j] = 0;

            else if (j == i)

                u[i][j] = 1;

            else
            {

                u[i][j] = a[i][j] / l[i][i];

                for (k = 0; k < i; k++)
                {

                    u[i][j] = u[i][j] - ((l[i][k] * u[k][j]) / l[i][i]);

                }

            }

        }

    }

}



int main()
{

    float a[10][10], l[10][10], u[10][10];

    int n = 0, i = 0, j = 0;



    cout << "Enter size of square matrix : "<<endl;

    cin >> n;



    cout<<"Enter matrix values: "<<endl;

    for (i = 0; i < n; i++)

        for (j = 0; j < n; j++)

            cin >> a[i][j];

    LUdecomposition(a, l, u, n);

    cout << "L Decomposition is as follows..."<<endl;

    for (i = 0; i < n; i++)
    {

        for (j = 0; j < n; j++)
        {

            cout<<l[i][j]<<" ";

        }

        cout << endl;

    }

    cout << "U Decomposition is as follows..."<<endl;

    for (i = 0; i < n; i++)
    {

        for (j = 0; j < n; j++)
        {

            cout<<u[i][j]<<" ";

        }

        cout << endl;

    }

    return 0;

}