методы вычислений Поплавский / Lagrang

#include <iostream>
#include <vector>

using namespace std;

int main() {
    setlocale(LC_ALL, "RUS");
    int n;
    cout << "Введите ваш номер варианта: ";
    cin >> n;
    system("cls");
    cout << "=== Введите значения X ===\n" << endl;
    vector <float> x, y;

    for (int i = 0; i < 4; i++) {
        cout << "Введите X [" << i << "]: ";
        int m;
        cin >> m;
        x.push_back(m);
        cout << endl;
    }

    for (int i = 0; i < 4; i++) {
        float m = (x[i] * x[i] * x[i]) / (n + 1);
        y.push_back(m);
    }
    cout << "X: ";
    for (int i = 0; i < 4; i++)
        cout << x[i] << " ";
    cout << endl;

    cout << "Y: ";
    for (int i = 0; i < 4; i++)
        cout << y[i] << " ";
    cout << "\n" << endl;
    vector <vector <int>> XX;
    for (int i = 0; i < 3; i++) {
        XX.push_back(vector<int>());
        for (int j = 0; j < 3; j++) {
            int m = (x[j] + x[j + 1]) / 2;
            XX[i].push_back(m * m * m);
            XX[i].push_back(m * m);
            XX[i].push_back(m);
        }
    }
    float l = ((XX[0][1] - x[1]) * (XX[0][1] - x[2]) * (XX[0][1] - x[3])) / ((x[0] - x[1]) * (x[0] - x[2]) * (x[0] - x[3]));
    float ll = ((XX[0][1] - x[0]) * (XX[0][1] - x[2]) * (XX[0][1] - x[3])) / ((x[1] - x[0]) * (x[1] - x[2]) * (x[1] - x[3]));
    float lll = ((XX[0][1] - x[0]) * (XX[0][1] - x[1]) * (XX[0][1] - x[3])) / ((x[2] - x[0]) * (x[2] - x[1]) * (x[2] - x[3]));
    system("pause");
    return 0;
}