[문자열 덧셈 계산기] 이승아 과제 제출합니다.

src/main/java/calculator/calculator.java

@@ -0,0 +1,61 @@
+package techCourse_calculator;
+
+import java.util.Scanner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class calculator {
+
+    public static int add(String input) {
+        if (input == null || input.isEmpty()) {
+            return 0;
+        }
+
+        String delimiter = ",|:";
+
+        Matcher matcher = Pattern.compile("//(.*)\n(.*)").matcher(input);
+
+        if (matcher.matches()) {
+            delimiter = Pattern.quote(matcher.group(1));
+            input = matcher.group(2);
+        }
+
+        String allowedChars = "[0-9" + delimiter.replace("|", "") + "]+";
+        String inputWithoutChars = input.replaceAll("\\s+", "");
+
+        if (!Pattern.matches("(" + allowedChars + ")+", inputWithoutChars.replaceAll(delimiter, ""))) {
+            throw new IllegalArgumentException("허용되지 않은 구분자/문자 포함 : " + input);
+        }
+
+        String[] tokens = input.split(delimiter);
+
+        int sum = 0;
+
+        for (String token : tokens) {
+            Matcher numMatcher = Pattern.compile("-?\\d+").matcher(token);
+            while (numMatcher.find()) {
+                int num = Integer.parseInt(numMatcher.group());
+                if (num < 0) {
+                    throw new IllegalArgumentException("양수와 구분자만 허용 : " + num);
+                }
+                sum += num;
+            }
+        }
+
+        return sum;
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+
+        System.out.println("덧셈할 문자열을 입력해 주세요.");
+        String input = sc.nextLine();
+
+        int result = add(input);
+        System.out.println("결과 : " + result);
+
+        sc.close();
+    }
+
+}
+