alpha beta

#include <stdio.h>

int main() {
    FILE *file;
    file = fopen("C:\\Users\\Vitaly\\CLionProjects\\mephi\\it_labs\\sem_I\\task_1\\input.txt", "r");
    if (file != NULL) {
       // printf("How many points?\n");
        int num_of_points = 0;
        fscanf(file, "%d", &num_of_points);
        float Array_x[num_of_points];
        float Array_y[num_of_points];
        float x = 0;
        float y = 0;
        float x_mid = 0;
        float y_mid = 0;
        for (int i = 0; i < num_of_points; ++ i) {
            fscanf(file, "%f%f", &x, &y);
            x_mid += x;
            y_mid += y;
            Array_x[i] = x;
            Array_y[i] = y;
        }
        fclose(file);
        x_mid /= (float) num_of_points;
        y_mid /= (float) num_of_points;
        float sum_up = 0;
        float sum_down = 0;
        for (int i = 0; i < num_of_points; ++ i) {
            sum_up  += (Array_x[i] - x_mid)*(Array_y[i] - y_mid);
            sum_down += (Array_x[i] - x_mid)*((Array_x[i] - x_mid));
        }
        float beta = sum_up/sum_down;
        float alpha = y_mid - beta*x_mid;
        printf("alpha = %f  beta = %f",alpha,beta);
    } else {
        printf("Something wrong with file.");
    }
}