refactor 75

Author: fishercoder1534

Diff for: src/main/java/com/fishercoder/solutions/_75.java

@@ -1,6 +1,9 @@
 package com.fishercoder.solutions;
 
-/** Given an array with n objects colored red, white or blue,
+/**
+ * 75. Sort Colors
+ *
+ * Given an array with n objects colored red, white or blue,
  * sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue.
 
  Here, we will use the integers 0, 1, and 2 to represent the color red, white, and blue respectively.
@@ -9,39 +12,34 @@
  You are not suppose to use the library's sort function for this problem.
 
  Follow up:
+
  A rather straight forward solution is a two-pass algorithm using counting sort.
  First, iterate the array counting number of 0's, 1's, and 2's,
  then overwrite array with total number of 0's, then 1's and followed by 2's.
+ Could you come up with an one-pass algorithm using only constant space?
+ */
 
- Could you come up with an one-pass algorithm using only constant space?*/
 public class _75 {
 
+  public static class Solution1 {
     public void sortColors(int[] nums) {
-        int zero = 0;
-        int two = nums.length - 1;
-        for (int i = 0; i <= two; ) {
-            if (nums[i] == 0 && i > zero) {
-                swap(nums, i, zero++);
-            } else if (nums[i] == 2 && i < two) {
-                swap(nums, i, two--);
-            } else {
-                i++;
-            }
+      int zero = 0;
+      int two = nums.length - 1;
+      for (int i = 0; i <= two; ) {
+        if (nums[i] == 0 && i > zero) {
+          swap(nums, i, zero++);
+        } else if (nums[i] == 2 && i < two) {
+          swap(nums, i, two--);
+        } else {
+          i++;
         }
+      }
     }
 
     void swap(int[] nums, int m, int n) {
-        int temp = nums[m];
-        nums[m] = nums[n];
-        nums[n] = temp;
-    }
-
-
-    public static void main(String... args) {
-//        int[] nums = new int[]{0,1,2,0,2,1};
-//        int[] nums = new int[]{0};
-//        int[] nums = new int[]{2};
-        int[] nums = new int[]{2, 2, 1};
-//        int[] nums = new int[]{1,0};
+      int temp = nums[m];
+      nums[m] = nums[n];
+      nums[n] = temp;
     }
+  }
 }

Diff for: src/test/java/com/fishercoder/_75Test.java

@@ -0,0 +1,52 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._75;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class _75Test {
+  private static _75.Solution1 solution1;
+  private static int[] nums;
+
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _75.Solution1();
+  }
+
+  @Test
+  public void test1() {
+    nums = new int[] {2, 2, 1};
+    solution1.sortColors(nums);
+    assertArrayEquals(new int[] {1, 2, 2}, nums);
+  }
+
+  @Test
+  public void test2() {
+    nums = new int[] {0, 1, 2, 0, 2, 1};
+    solution1.sortColors(nums);
+    assertArrayEquals(new int[] {0, 0, 1, 1, 2, 2}, nums);
+  }
+
+  @Test
+  public void test3() {
+    nums = new int[] {0};
+    solution1.sortColors(nums);
+    assertArrayEquals(new int[] {0}, nums);
+  }
+
+  @Test
+  public void test4() {
+    nums = new int[] {1, 0};
+    solution1.sortColors(nums);
+    assertArrayEquals(new int[] {0, 1}, nums);
+  }
+
+  @Test
+  public void test5() {
+    nums = new int[] {2};
+    solution1.sortColors(nums);
+    assertArrayEquals(new int[] {2}, nums);
+  }
+}