refactor 66

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_66.java

@@ -1,52 +1,44 @@
 package com.fishercoder.solutions;
 
-import com.fishercoder.common.utils.CommonUtils;
-
-/**66. Plus One
-Given a non-negative number represented as an array of digits, plus one to the number.
-
-The digits are stored such that the most significant digit is at the head of the list.*/
+/**
+ * 66. Plus One
+ *
+ * Given a non-negative number represented as an array of digits, plus one to the number. The digits
+ * are stored such that the most significant digit is at the head of the list.
+ */
 public class _66 {
-    //also looked at Discuss, basically the same idea as mine, just their code is more concise.
 
+  public static class Solution1 {
     public int[] plusOne(int[] digits) {
-        boolean carry = false;
-        int len = digits.length;
-        int[] temp = digits;
-        //process the last digit at first, to get carry value
-        if (digits[len - 1] + 1 == 10) {
-            carry = true;
-            temp[len - 1] = 0;
-        } else {
-            temp[len - 1] += 1;
-            return temp;
-        }
-
-        //start from the second last element
-        for (int i = len - 2; i >= 0; i--) {
-            if (carry && temp[i] + 1 == 10) {
-                temp[i] = 0;
-                carry = true;
-            } else if (carry) {
-                temp[i] += 1;
-                carry = false;
-            }
-        }
-        if (carry && temp[0] == 0) {
-            int[] res = new int[len + 1];
-            res[0] = 1;
-            //all the rest of the numbers should all be zeroes, so we don't need to copy from the original array
-            return res;
-        }
+      boolean carry = false;
+      int len = digits.length;
+      int[] temp = digits;
+      //process the last digit at first, to get carry value
+      if (digits[len - 1] + 1 == 10) {
+        carry = true;
+        temp[len - 1] = 0;
+      } else {
+        temp[len - 1] += 1;
         return temp;
-    }
+      }
 
-    public static void main(String... strings) {
-        _66 test = new _66();
-//        int[] digits = new int[]{9,9,9,9};
-//        int[] digits = new int[]{8,9,9,9};
-        int[] digits = new int[]{2, 4, 9, 3, 9};
-        int[] res = test.plusOne(digits);
-        CommonUtils.printArray(res);
+      //start from the second last element
+      for (int i = len - 2; i >= 0; i--) {
+        if (carry && temp[i] + 1 == 10) {
+          temp[i] = 0;
+          carry = true;
+        } else if (carry) {
+          temp[i] += 1;
+          carry = false;
+        }
+      }
+      if (carry && temp[0] == 0) {
+        int[] res = new int[len + 1];
+        res[0] = 1;
+        //all the rest of the numbers should all be zeroes, so we don't need to copy from the original array
+        return res;
+      }
+      return temp;
     }
+  }
 }

src/test/java/com/fishercoder/_66Test.java

@@ -0,0 +1,35 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._66;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class _66Test {
+  private static _66.Solution1 solution1;
+  private static int[] digits;
+
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _66.Solution1();
+  }
+
+  @Test
+  public void test1() {
+    digits = new int[] {9, 9, 9, 9};
+    assertArrayEquals(new int[] {1, 0, 0, 0, 0}, solution1.plusOne(digits));
+  }
+
+  @Test
+  public void test2() {
+    digits = new int[] {8, 9, 9, 9};
+    assertArrayEquals(new int[] {9, 0, 0, 0}, solution1.plusOne(digits));
+  }
+
+  @Test
+  public void test3() {
+    digits = new int[] {2, 4, 9, 3, 9};
+    assertArrayEquals(new int[] {2, 4, 9, 4, 0}, solution1.plusOne(digits));
+  }
+}