Studio 10

Studio Worksheets

1. Studio 10 Worksheet
2. Studio 10 In-class Worksheet

Visualizing mem 👀

display_2D_mem is a helper function to visualize the cache of your memoized function. You can use this function to help you debug your memoized function.

Feel free to try this out for the coin change problem in this week’s studio worksheet

// Array -> void
function display_2D_mem(mem) {
  function pad_right(str, char, num) {
    return num === 0 ? str : pad_right(str + char, char, num - 1);
  }

  const num_keys = array_length(mem);
  const num_values = accumulate(
    (idx, max) =>
      is_undefined(mem[idx]) ? max : math_max(array_length(mem[idx]), max),
    -1,
    build_list((x) => x, num_keys)
  );

  const max_key_length = array_length(stringify(num_keys - 1));

  for (let key = 0; key < num_keys; key = key + 1) {
    let val_store = is_undefined(mem[key]) ? [] : mem[key];
    if (array_length(val_store) < num_values) {
      val_store[num_values - 1] = undefined;
    }

    let val_str = "[";
    for (let val_idx = 0; val_idx < num_values; val_idx = val_idx + 1) {
      val_str = val_str + (is_undefined(val_store[val_idx]) ? " " : "X");
      val_str = val_str + (val_idx < num_values - 1 ? " " : "");
    }
    val_str = val_str + "]";

    display(
      val_str,
      pad_right(
        stringify(key) + ":",
        " ",
        max_key_length - array_length(stringify(key))
      )
    );
  }
}

// Sample usage
// display_2d_mem(mem) where mem is your cache for your memoized function