리팩토링: 코드 최적화

lib/engine/parenthesis-sign.ts

@@ -25,7 +25,12 @@ function formatLatexTermPair(first: number, second: number) {
   return `${first} ${operator} ${Math.abs(second)}`;
 }
 
-function createProblem({ multiplier, a, operator, b }: ProblemSeed) {
+function createProblem({
+  multiplier,
+  a,
+  operator,
+  b,
+}: ProblemSeed): ParenthesisSignProblem {
   const distributedA = multiplier * a;
   const distributedB = operator === "-" ? multiplier * -b : multiplier * b;
   const key = `${multiplier}:${a}:${operator}:${b}`;
@@ -65,6 +70,8 @@ function createAllProblemSeeds() {
   return seeds;
 }
 
+const ALL_PROBLEM_SEEDS = createAllProblemSeeds();
+
 function shuffle<T>(items: T[]) {
   const shuffled = [...items];
 
@@ -103,7 +110,7 @@ export function generateSession(count = 10): ParenthesisSignProblem[] {
     throw new Error(`count cannot exceed ${MAX_PROBLEM_COUNT}.`);
   }
 
-  return shuffle(createAllProblemSeeds()).slice(0, count).map(createProblem);
+  return shuffle(ALL_PROBLEM_SEEDS).slice(0, count).map(createProblem);
 }
 
 export function gradeAnswer(