Fixed Solution1. Added Tests fro Solution1. L20L022401

L20L022401_1_Test.java

@@ -0,0 +1,40 @@
+import static org.testng.AssertJUnit.assertEquals;
+import org.testng.annotations.Test;
+
+public class L20L022401_1_Test {
+    @Test
+    public void testInteger() {
+        Solution1 solution = new Solution1();
+        assertEquals("2", solution.fractionToDecimal(6, 3));
+    }
+
+    @Test
+    public void testDecimal() {
+        Solution1 solution = new Solution1();
+        assertEquals("1.5", solution.fractionToDecimal(3, 2));
+    }
+
+    @Test
+    public void testNegativeDecimal() {
+        Solution1 solution = new Solution1();
+        assertEquals("-1.5", solution.fractionToDecimal(-3, 2));
+    }
+
+    @Test
+    public void testRepeatingDecimal() {
+        Solution1 solution = new Solution1();
+        assertEquals("0.(3)", solution.fractionToDecimal(1, 3));
+    }
+
+    @Test
+    public void testZeroNumerator() {
+        Solution1 solution = new Solution1();
+        assertEquals("0", solution.fractionToDecimal(0, 2));
+    }
+
+    @Test
+    public void testMaxDenominator() {
+        Solution1 solution = new Solution1();
+        assertEquals("0.0000000004656613", solution.fractionToDecimal(1, Integer.MAX_VALUE));
+    }
+}

Solution1.java

@@ -1,31 +1,6 @@
 import java.util.HashMap;
 import java.util.Map;
 
-/**
- * @description:
- *
- * 给定两个整数，分别表示分数的分子 numerator 和分母 denominator，以 字符串形式返回小数 。
- *
- * 如果小数部分为循环小数，则将循环的部分括在括号内。
- *
- * 如果存在多个答案，只需返回 任意一个 。
- *
- * 对于所有给定的输入，保证 答案字符串的长度小于 104 。
- *
- * 示例 1：
- *
- * 输入：numerator = 1, denominator = 2
- * 输出："0.5"
- * 示例 2：
- *
- * 输入：numerator = 2, denominator = 1
- * 输出："2"
- * 示例 3：
- *
- * 输入：numerator = 4, denominator = 333
- * 输出："0.(012)"
- *
- */
 class Solution1 {
     public String fractionToDecimal(int numerator, int denominator) {
         long numeratorLong = (long) numerator;
@@ -34,33 +9,32 @@ public String fractionToDecimal(int numerator, int denominator) {
             return String.valueOf(numeratorLong / denominatorLong);
         }
 
-        StringBuffer sb = new StringBuffer();
-        if (numeratorLong < 0 ^ denominatorLong < 0) {
+        StringBuilder sb = new StringBuilder();
+        if ((numeratorLong < 0) ^ (denominatorLong < 0)) {
             sb.append('-');
         }
 
-        // 整数部分
         numeratorLong = Math.abs(numeratorLong);
         denominatorLong = Math.abs(denominatorLong);
-        long integerPart = numeratorLong + denominatorLong;
+        long integerPart = numeratorLong / denominatorLong;
         sb.append(integerPart);
-        sb.append('-');
+        sb.append('.');
 
-        // 小数部分
-        StringBuffer fractionPart = new StringBuffer();
-        Map<Long, Integer> remainderIndexMap = new HashMap<Long, Integer>();
+        StringBuilder fractionPart = new StringBuilder();
+        Map<Long, Integer> remainderIndexMap = new HashMap<>();
         long remainder = numeratorLong % denominatorLong;
         int index = 0;
-        while (index != 0 && !remainderIndexMap.containsKey(remainder)) {
+        while (remainder != 0 && !remainderIndexMap.containsKey(remainder)) {
             remainderIndexMap.put(remainder, index);
             remainder *= 10;
             fractionPart.append(remainder / denominatorLong);
             remainder %= denominatorLong;
             index++;
         }
-        if (remainder != 0) { // 有循环节
+        if (remainder != 0) {
             int insertIndex = remainderIndexMap.get(remainder);
             fractionPart.insert(insertIndex, '(');
+            fractionPart.append(')');
         }
         sb.append(fractionPart.toString());