괄호 안의 항을 2, 3, 4 항으로 설정하는 기능 추가

lib/engine/types.ts

@@ -2,9 +2,12 @@ export interface ParenthesisSignProblem {
   id: string;
   key: string;
   multiplier: number;
+  terms: number[];
+  operators: ("+" | "-")[];
   a: number;
   operator: "+" | "-";
   b: number;
+  distributedTerms: number[];
   distributedA: number;
   distributedB: number;
   latexBefore: string;
@@ -12,12 +15,13 @@ export interface ParenthesisSignProblem {
 }
 
 export interface UserAnswer {
-  a: number;
-  b: number;
+  terms?: number[];
+  a?: number;
+  b?: number;
 }
 
 export interface GradeResult {
   correct: boolean;
-  userAnswer: [number, number];
-  correctAnswer: [number, number];
+  userAnswer: number[];
+  correctAnswer: number[];
 }