#include <stdio.h>
#include <stdlib.h>

#define NUM_ROWS 3

int main() {
  /**
   * In this demo, we'll be creating an irregular 2D array with 3 rows.
   */
  int **array = NULL;
  int numCols;

  int len[3]; // array to store row length for printing only, you can disregard this

  // 1. First Dimension
  array = (int**) malloc(sizeof(int *) * NUM_ROWS);

  // 2. Second Dimension
  for (int row = 0; row < NUM_ROWS; row++) {
    do {
      // Prompt for number of rows
      printf("Number of columns for row %i: ", row + 1);
      scanf("%i", &numCols);

      len[row] = numCols; // store current number; disregard this
    } while (numCols < 1);

    // Allocate number of row
    array[row] = (int*) malloc(sizeof(int) * numCols);

    // Pre-fill array
    for (int col = 0; col < numCols; col++) {
      array[row][col] = numCols;
    }
  }

  // Printing
  printf("\n");
  for (int row = 0; row < NUM_ROWS; row++) {
    printf("ROW %i:  ", row + 1);
    for (int col = 0; col < len[row]; col++) {
      printf("[%2i] ", array[row][col]);
    }
    printf("\n");
  }

  // Freeing
  for (int row = 0; row < NUM_ROWS; row++) {
    free(array[row]);
  }

  return 0;
}