Advent of PBT 2021 - Day 10

/**
 * Compute the minimal number of changes to be applied onto stringA
 * to change it into stringB.
 * In other words: Compute the distance of Levenshtein between
 * two strings.
 *
 * @param stringA - The first string to be taken into account
 * @param stringB - The second string to be taken into account
 *
 * @returns
 * Minimal number of single-character edits (insertions, deletions or
 * substitutions) to be applied onto stringA to change it into
 * stringB.
 */
declare function minimalNumberOfChangesToBeOther(
  stringA: string,
  stringB: string
): number;

it("should not consider any change to move to same value", () => {
  const out = minimalNumberOfChangesToBeOther("azerty", "azerty");
  expect(out).toBe(0);
});

it("should properly handle added characters", () => {
  const out = minimalNumberOfChangesToBeOther("azerty", "0aze5rty9");
  expect(out).toBe(3); // add: 0, 5, 9
});

it("should properly handle removed characters", () => {
  const out = minimalNumberOfChangesToBeOther("0aze5rty9", "azerty");
  expect(out).toEqual(3); // remove: 0, 5, 9
});

it("should properly handle updated characters", () => {
  const out = minimalNumberOfChangesToBeOther("azerty", "AzERTy");
  expect(out).toEqual(4); // update: a->A, e->E, r->R, t->T
});

it("should properly handle mix of add/remove/update", () => {
  const out = minimalNumberOfChangesToBeOther("azerty", "0az1eRt");
  expect(out).toEqual(4); // add: 0, 1, remove: y, update: r->R
});