Least Square Fit Method by Me

#include <iostream>
#include <cstdlib>
#include <cmath>

using namespace std;

class LeastSquareFit{
    double **A, *X, *B, *x, *y;
    double *sum_x, *sum_yx;
    int m, n;
    public:
        LeastSquareFit(int, int);
        ~LeastSquareFit();
        void input();
        void calcSumX();
        void calcSumYX();
        void calcAMatrix();
        void calcBMatrix();
        void performGaussElimination();
        void display();
};

void LeastSquareFit::performGaussElimination(){
    int i, j, k;
    double multiplication_factor;
    // Obtaining triangular equations
    for(k = 1; k <= n-1; k++){
        for(i = k + 1; i <= n; i++){
            multiplication_factor = -(A[k][k] / A[i][k]);
            for(j = 1; j <= n; j++){
                A[i][j] = A[k][j] + (multiplication_factor * A[i][j]);
            }
            B[i] = B[k] + (multiplication_factor * B[i]);
        }
    }
    // Applying back substitution to obtain the solution
    X[n] = B[n] / A[n][n];
    double sum;
    for(i = n - 1; i >= 1; i--){
        sum = 0;
        for(j = i + 1; j <= n; j++){
            sum += A[i][j] * X[j];
        }
        X[i] = (B[i] - sum) / A[i][i];
    }
}

LeastSquareFit::~LeastSquareFit(){
    delete[] x;
    delete[] y;
    delete[] X;
    delete[] B;
    delete[] sum_x;
    delete[] sum_yx;
    for(int i = 0; i < (LeastSquareFit::n + 1); i++){
        delete[] A[i];
    }
}

LeastSquareFit::LeastSquareFit(int m, int n){
    LeastSquareFit::m = m;
    LeastSquareFit::n = n;
    x = new double[LeastSquareFit::m];
    y = new double[LeastSquareFit::m];
    X = new double[LeastSquareFit::n + 1];
    B = new double[LeastSquareFit::n + 1];
    A = new double*[LeastSquareFit::n + 1];
    for(int i = 0; i < (LeastSquareFit::n + 1); i++){
        A[i] = new double[LeastSquareFit::n + 1];
    }
    sum_x = new double[(LeastSquareFit::n * LeastSquareFit::n) + 1];
    sum_yx = new double[LeastSquareFit::n + 1];
}

void LeastSquareFit::calcSumX(){
    sum_x[0] = 1;
    int limit = n * n;
    for(int i = 1; i <= limit; i++){
        sum_x[i] = 0;
        for(int j = 0; j < m; j++){
            sum_x[i] += pow(x[j], i);
        }
    }
}

void LeastSquareFit::calcSumYX(){
    int limit = n + 1;
    for(int i = 0; i < limit; i++){
        sum_yx[i] = 0;
        for(int k = 0; k < m; k++){
            sum_yx[i] += (y[k] * pow(x[k], i));
        }
    }
}

void LeastSquareFit::calcAMatrix(){
    A[0][0] = m;
    int rows = n + 1;
    int cols = n + 1;
    for(int i = 0; i < rows; i++){
        for(int j = 0; j < cols; j++){
            if(i != 0 || j != 0){
                A[i][j] = sum_x[i + j];
            }
        }
    }
}

void LeastSquareFit::calcBMatrix(){
    int limit = n + 1;
    for(int i = 0; i < limit; i++){
        B[i] = sum_yx[i];
    }
}

void LeastSquareFit::input(){
    for(int i = 0; i < m; i++){
        cout << "x[" << i << "] = ";
        cin >> x[i];
        cout << "y[" << i << "] = ";
        cin >> y[i];
    }
}

void LeastSquareFit::display(){
    calcSumX();
    calcSumYX();
    calcAMatrix();
    calcBMatrix();
    cout << "Displaying A matrix\n";
    int rows = n + 1;
    int cols = n + 1;
    for(int i = 0; i < rows; i++){
        for(int j = 0; j < cols; j++){
            cout << A[i][j] << "\t";
        }
        cout << endl;
    }
    cout << "\nDisplaying B matrix\n";
    int limit = n + 1;
    for(int i = 0; i < limit; i++){
            cout << B[i] << "\n";
    }
    cout << "\nDisplaying sum_yx matrix\n";
    for(int i = 0; i < limit; i++){
            cout << sum_yx[i] << ",";
    }
    cout << "\nDisplaying sum_yx matrix\n";
    limit = (n * n) + 1;
    for(int i = 0; i < limit; i++){
            cout << sum_x[i] << ",";
    }
    performGaussElimination();
    cout << "\n\nDisplaying Triangular matrix\n";
    for(int i = 0; i < rows; i++){
        for(int j = 0; j < cols; j++){
            cout << A[i][j] << "\t";
        }
        cout << endl;
    }
}

int main(){
    int n, m;
    system("cls");
    cout << "Enter the degree of polynomial: ";
    cin >> n;
    cout << "Enter the number of points in experiment: ";
    cin >> m;
    LeastSquareFit obj(m, n);
    obj.input();
    obj.display();
    cin.ignore();
    cin.get();
    return 0;
}