1차 작성

src/main/java/Calculator.java

@@ -0,0 +1,23 @@
+public class Calculator {
+
+    public int add(int fir, int sec) {
+        return fir + sec;
+    }
+
+    public int subtract(int fir, int sec) {
+        return fir - sec;
+    }
+
+    public int multiply(int fir, int sec) {
+        return fir * sec;
+    }
+
+    public int divide(int fir, int sec) {
+        if (sec == 0) {
+            throw new ArithmeticException("Divide by zero");
+        }
+        return fir / sec;
+    }
+
+
+}

src/main/java/StringCalculator.java

@@ -0,0 +1,40 @@
+public class StringCalculator {
+
+    public int add(String string) {
+        if (string.isEmpty()) {
+            return 0;
+        }
+
+
+        String[] numbers = string.split(",|:");
+        return sum(numbers);
+    }
+
+    private int sum(String[] numbers) {
+        int total = 0;
+
+        for (String number : numbers) {
+            int num = checkNumber(number);
+            total += num;
+        }
+
+        return total;
+    }
+
+    private int checkNumber(String number) {
+        if (number.isEmpty()) {
+            return 0;
+        }
+
+        // 숫자가 아닌 경우 RuntimeException 발생
+        try {
+            int num = Integer.parseInt(number);
+            if (num < 0) {
+                throw new RuntimeException("음수가 포함되어 있습니다.");
+            }
+            return num;
+        } catch (NumberFormatException e) {
+            throw new RuntimeException("잘못된 입력입니다.");
+        }
+    }
+}

src/test/java/CalculatorTest.java

@@ -0,0 +1,15 @@
+public class CalculatorTest {
+
+    public static void main(String[] args) {
+
+        Calculator calc = new Calculator();
+
+        System.out.println(calc.add(10, 20));
+        System.out.println(calc.add(10, -5));
+        System.out.println(calc.subtract(10, 20));
+        System.out.println(calc.multiply(10, 20));
+        System.out.println(calc.divide(10, 5));
+
+
+    }
+}

src/test/java/StringCalculatorTest.java

@@ -0,0 +1,46 @@
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+public class StringCalculatorTest {
+
+    private final StringCalculator calculator = new StringCalculator();
+
+    @Test
+    public void testEmptyString() {
+        assertEquals(0, calculator.add(""));
+    }
+
+
+    @Test
+    public void testNumbers() {
+        assertEquals(3, calculator.add("1,2"));
+        assertEquals(7, calculator.add("3:4"));
+        assertEquals(6, calculator.add("1,2,3"));
+        assertEquals(10, calculator.add("4:2:4"));
+        assertEquals(15, calculator.add("1,2:3,4,5"));
+    }
+
+    @Test
+    public void testNegativeNumber() {
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> {
+            calculator.add("1,-2");
+        });
+        assertEquals("음수가 포함되어 있습니다.", exception.getMessage());
+    }
+
+    @Test
+    public void testInvalidString() {
+        RuntimeException exception = assertThrows(RuntimeException.class, () -> {
+            calculator.add("1,a");
+        });
+        assertEquals("잘못된 입력입니다.", exception.getMessage());
+    }
+
+    @Test
+    public void testMixedDelimiters() {
+        assertEquals(10, calculator.add("1,2:3,4"));
+        assertEquals(15, calculator.add("1,2:3,4,5"));
+    }
+}
+
+