LAB_17 fill arrays by different ways

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>

#define FILE_NAME "numbers.txt"
#define FILE_NUMBERS_ARRAY_SIZE 10

void printArray(const int a[], int n) {
    printf("\n");
    printf("\n");
    printf("[");
    for(int i = 0; i < n; i++) {

        // printf with no dividers
        if(i + 1 == n) {
            printf("%d", a[i]);
        } else {
            printf("%d, ", a[i]);
        }
    }
    printf("]");
    printf("\n");
    printf("\n");
}

void printTwoDimensionalArray(int n, const int a[n][n]) {
    printf("\n");
    printf("\n");
    for(int i = 0; i < n; i++) {
        printf("row %d -  ", i);
        for(int j = 0; j < n; j ++) {
            printf(" %d ", a[i][j]);
        }
        printf("\n");
    }
    printf("\n");
    printf("\n");
}

void fill_array_via_key_board(int size) {
    int array[size][size];
    for(int i = 0; i < size; i++) {
        for(int j = 0; j < size; j++) {
            array[i][j] = j;
        }
    }

    printf("Print the 2d keyboard's array");
    printTwoDimensionalArray(size, array);
}

void fill_array_via_file(int size) {
    int numbers[FILE_NUMBERS_ARRAY_SIZE];
    int array[size][size];

    FILE *f = fopen(FILE_NAME, "r");

    if(f != NULL) { // file exists
        int n = 0;
        while(!feof(f)) {
            fscanf(f, "%d", &numbers[n++]);
        }
    } else {
        printf("file does not exist yet");
    }
    fclose(f);

    printf("\nPrint the file's array");
    printArray(numbers, FILE_NUMBERS_ARRAY_SIZE);

    //fill the 2d array by default values
    for(int i = 0; i < size; i++) {
        for(int j = 0; j < size; j ++) {
             array[i][j] = 0;
        }
    }

    // fill the 2d array by the file's numbers
    int currentIndexRow2dArray = -1;
    int currentIndexColumn2dArray = -1;
    for(int i = 0; i < FILE_NUMBERS_ARRAY_SIZE; i++) {
        if(i % size == 0) {
            currentIndexRow2dArray++;
            currentIndexColumn2dArray = -1;
        }
        currentIndexColumn2dArray++;
        int fileNumber = numbers[i];

        array[currentIndexRow2dArray][currentIndexColumn2dArray] = fileNumber;
    }

    printf("\nPrint the 2d file's array");
    printTwoDimensionalArray(size, array);
}

void fill_array_via_range(int size) {
    int array[size][size];

    int A, B;
    printf("Введите range.");

    printf("\nstart: ");
    scanf("%d", &A);

    printf("end: ");
    scanf("%d", &B);

    if(A > B) {
        int temp = A;
        A = B;
        B = temp;
    }

    for(int i = 0; i < size; i++) {
        for(int j = 0; j < size; j++) {
            int randomNumber = rand() % (B - A + 1) + A;
            array[i][j] = randomNumber;
        }
    }

    printf("\nPrint the 2d random range's array");
    printTwoDimensionalArray(size, array);
}

int calculatedElementByFormula(int i, int j) {
    int element = i + j;
    if(i < j) {
        element = i - j;
    } else {
        if (i == j)
        {
            if(j != 0) {
                element = i/j;
            }
        }
    }
    return element;
}

void fill_array_via_formula(int size) {
    int array[size][size];

     for(int i = 0; i < size; i++) {
        for(int j = 0; j < size; j++) {
            int element = calculatedElementByFormula(i, j);
            array[i][j] = element;
        }
    }

    printf("\nPrint the 2d formulas' array");
    printTwoDimensionalArray(size, array);
}


void task_1() {
    int n;

    printf("\nEnter n to define the size of the array(N x N): ");
    scanf("%d", &n);
    if(n <= 0) {
        printf("\nn must be more than zero");
    } else {
        int array[n][n];
        int wayOfFilling;

        printf("\nEnter the way of filling the array: ");

        printf("\n1 - Via KeyBoard");
        printf("\n2 - Via File");
        printf("\n3 - Via Random numbers in range");
        printf("\n4 - Via Formula: ");

        printf("\n");

        scanf("%d", &wayOfFilling);

        switch(wayOfFilling) {
            case 1: fill_array_via_key_board(n); break;
            case 2: fill_array_via_file(n); break;
            case 3: fill_array_via_range(n); break;
            case 4: fill_array_via_formula(n); break;
            default: printf("Way by %d is not defined", wayOfFilling);
        }

    }
}

int main() {
    int numOfTask = 0;
    do
    {
        printf("\nEnter a number of the task: ");
        scanf("%d", &numOfTask);

        switch (numOfTask) {
        case 1:
            task_1();
            break;
        default:
            printf("\nThe task by num %d has not found", numOfTask);
            break;
        }

    } while (numOfTask != 0);

    return 0;
}