refactor: MONOREPO

frontend/src/algorithms/levenshtein/__tests__/levenshtein.test.ts

@@ -0,0 +1,21 @@
+import { lev, levW } from "../";
+
+test("lev(abc, abc) == 0", () => {
+    expect(lev("abc", "abc", 3, 3)).toBe(0);
+    expect(levW("abc", "abc")).toBe(0);
+});
+
+test("lev(abc, abd) == 1", () => {
+    expect(lev("abc", "abd", 3, 3)).toBe(1);
+    expect(levW("abc", "abd")).toBe(1);
+});
+
+test("lev(abc, abcd) == 1", () => {
+    expect(lev("abc", "abcd", 3, 4)).toBe(1);
+    expect(levW("abc", "abcd")).toBe(1);
+});
+
+test("lev(abcd, bcd) == 1", () => {
+    expect(lev("abcd", "bcd", 4, 3)).toBe(1);
+    expect(levW("abcd", "bcd")).toBe(1);
+});

frontend/src/algorithms/levenshtein/index.ts

@@ -0,0 +1,30 @@
+function one(a: string, b: string, i: number, j: number): number {
+    if (a[i] === b[j]) {
+        return 0;
+    }
+
+    return 1;
+}
+
+// Computes the difference between the strings a and b.
+// @a, b: The strings to compare
+// @i, j: From where to compare (a_i and b_j)
+// @ret : The distance in insertions, deletions and changes
+export function lev(a: string, b: string, i: number, j: number): number {
+    if (Math.min(i, j) === 0) {
+        return Math.max(i, j);
+    } else {
+        return Math.min(
+            lev(a, b, i - 1, j) + 1,
+            lev(a, b, i, j - 1) + 1,
+            lev(a, b, i - 1, j - 1) + one(a, b, i, j)
+        );
+    }
+};
+
+// Computes the difference between the strings a and b.
+// @a, b: The strings to compare
+// @ret : The distance in insertions, deletions and changes
+export function levW(a: string, b: string): number {
+    return lev(a, b, a.length, b.length);
+}

frontend/src/algorithms/sm2/index.ts

@@ -0,0 +1,35 @@
+import { dayInNDays } from "../../utils/date";
+
+export interface ISchedulingData {
+    easiness: number;
+    consecutiveCorrectAnswers: number;
+    nextDueDate: number;
+};
+
+export enum AnswerType {
+    CORRECT,
+    WRONG,
+};
+
+function performanceRating(answer: AnswerType): number {
+    switch (answer) {
+        case AnswerType.WRONG:
+            return 1;
+        case AnswerType.CORRECT:
+            return 4;
+    }
+}
+
+export function updateSchedulingData(data: ISchedulingData, answer: AnswerType): ISchedulingData {
+    const perfRating = performanceRating(answer);
+
+    data.easiness += -0.8 + 0.28 * perfRating + 0.02 * Math.pow(perfRating, 2);
+    data.consecutiveCorrectAnswers = answer === AnswerType.CORRECT ? (
+        data.consecutiveCorrectAnswers + 1
+    ) : 0;
+    data.nextDueDate = answer === AnswerType.CORRECT ? (
+        dayInNDays(6 * Math.pow(data.easiness, data.consecutiveCorrectAnswers - 1))
+    ) : dayInNDays(1);
+
+    return data;
+}