refactor 415

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_415.java

@@ -1,47 +1,51 @@
 package com.fishercoder.solutions;
 
 /**
+ * 415. Add Strings
+ *
  * Given two non-negative numbers num1 and num2 represented as string, return the sum of num1 and num2.
 
  Note:
 
- The length of both num1 and num2 is < 5100.
- Both num1 and num2 contains only digits 0-9.
- Both num1 and num2 does not contain any leading zero.
- You must not use any built-in BigInteger library or convert the inputs to integer directly.
+ 1. The length of both num1 and num2 is < 5100.
+ 2. Both num1 and num2 contains only digits 0-9.
+ 3. Both num1 and num2 does not contain any leading zero.
+ 4. You must not use any built-in BigInteger library or convert the inputs to integer directly.
  */
 public class _415 {
 
-    public static String addStrings(String num1, String num2) {
-        if (num1 == null || num1.length() == 0) {
-            return num2;
-        } else if (num2 == null || num2.length() == 0) {
-            return num1;
-        }
+    public static class Solution1 {
+        public String addStrings(String num1, String num2) {
+            if (num1 == null || num1.length() == 0) {
+                return num2;
+            } else if (num2 == null || num2.length() == 0) {
+                return num1;
+            }
 
-        int i = num1.length() - 1;
-        int j = num2.length() - 1;
-        long carry = 0;
-        long sum = 0;
-        StringBuilder sb = new StringBuilder();
-        char[] char1 = num1.toCharArray();
-        char[] char2 = num2.toCharArray();
-        while (i >= 0 || j >= 0) {
-            sum = carry;
-            if (i >= 0) {
-                sum += Character.getNumericValue(char1[i--]);
+            int i = num1.length() - 1;
+            int j = num2.length() - 1;
+            long carry = 0;
+            long sum = 0;
+            StringBuilder sb = new StringBuilder();
+            char[] char1 = num1.toCharArray();
+            char[] char2 = num2.toCharArray();
+            while (i >= 0 || j >= 0) {
+                sum = carry;
+                if (i >= 0) {
+                    sum += Character.getNumericValue(char1[i--]);
+                }
+                if (j >= 0) {
+                    sum += Character.getNumericValue(char2[j--]);
+                }
+                carry = sum / 10;
+                sb.append(sum % 10);
             }
-            if (j >= 0) {
-                sum += Character.getNumericValue(char2[j--]);
+            if (carry != 0) {
+                sb.append(carry);
             }
-            carry = sum / 10;
-            sb.append(sum % 10);
-        }
-        if (carry != 0) {
-            sb.append(carry);
-        }
 
-        return sb.reverse().toString();
+            return sb.reverse().toString();
+        }
     }
 
 }

src/test/java/com/fishercoder/_415Test.java

@@ -7,19 +7,16 @@
 
 import static junit.framework.Assert.assertEquals;
 
-/**
- * Created by fishercoder on 1/8/17.
- */
 public class _415Test {
-    private static _415 test;
+    private static _415.Solution1 solution1;
     private static String expected;
     private static String actual;
     private static String num1;
     private static String num2;
 
     @BeforeClass
     public static void setup() {
-        test = new _415();
+        solution1 = new _415.Solution1();
         expected = new String();
         actual = new String();
         num1 = new String();
@@ -40,7 +37,7 @@ public void test1() {
         num1 = "123";
         num2 = "34567";
         expected = "34690";
-        actual = test.addStrings(num1, num2);
+        actual = solution1.addStrings(num1, num2);
         assertEquals(expected, actual);
 
     }
@@ -51,7 +48,7 @@ public void test2() {
         num1 = "1";
         num2 = "9";
         expected = "10";
-        actual = test.addStrings(num1, num2);
+        actual = solution1.addStrings(num1, num2);
         assertEquals(expected, actual);
 
     }
@@ -62,7 +59,7 @@ public void test3() {
         num1 = "9";
         num2 = "99";
         expected = "108";
-        actual = test.addStrings(num1, num2);
+        actual = solution1.addStrings(num1, num2);
         assertEquals(expected, actual);
 
     }