refactor 27

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_27.java

@@ -11,70 +11,20 @@
 Example:
 Given input array nums = [3,2,2,3], val = 3
 
-Your function should return length = 2, with the first two elements of nums being 2.*/
-public class _27 {
-    //then I looked at the Editorial solution, really neat!!! Super elegant and smart!
-	public int removeElement_editorial_solution_1(int[] nums, int val) {
-		//use two pointers, increment j as long as its not equal to val, return i in the end
-		int i = 0;
-		for (int j = 0; j < nums.length; j++) {
-			if (nums[j] != val) {
-				nums[i++] = nums[j];
-			}
-		}
-		return i;
-	}
-
-	public int removeElement_editorial_solution_2(int[] nums, int val) {
-		//this approach is very similar to the one below that I came up totally by myself, but it's much concise
-		//Here, it didn't check whether nums[n-1] will be equal to val, because in the next iteration, it will still check that number, smart!
-		int i = 0;
-		int n = nums.length;
-		while (i < n) {
-			if (nums[i] == val) {
-				nums[i] = nums[n - 1];
-				n--;
-			} else {
-				i++;
-			}
-		}
-		return i;
-	}
-
-	//just throw all numbers that are equal to val to the end and make a count of it
-	public int removeElement(int[] nums, int val) {
-		int count = 0;
-		int len = nums.length;
-		int throwPosition = len - 1;
-		for (int i = 0; i <= throwPosition; i++) {
-			while (throwPosition >= 0 && nums[throwPosition] == val) {
-				throwPosition--;
-				count++;
-			}
-			if (throwPosition == -1 || i >= throwPosition) {
-				break;
-			}
-			if (nums[i] == val) {
-				count++;
-				int temp = nums[throwPosition];
-				nums[throwPosition] = nums[i];
-				nums[i] = temp;
-				throwPosition--;
-			}
-		}
-		return len - count;
-	}
+Your function should return length = 2, with the first two elements of nums being 2.
+ */
 
-	public static void main(String... strings) {
-		_27 test = new _27();
-//		int[] nums = new int[]{3,2,2,3};
-//		int val = 3;
-
-		int[] nums = new int[]{2, 2, 3};
-		int val = 2;
+public class _27 {
 
-//		int[] nums = new int[]{1};
-//        int val = 1;
-		System.out.println(test.removeElement(nums, val));
-	}
-}
+  public static class Solution1 {
+    public int removeElement(int[] nums, int val) {
+      int i = 0;
+      for (int j = 0; j < nums.length; j++) {
+        if (nums[j] != val) {
+          nums[i++] = nums[j];
+        }
+      }
+      return i;
+    }
+  }
+}

src/test/java/com/fishercoder/_27Test.java

@@ -0,0 +1,36 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._27;
+import com.fishercoder.solutions._734;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static junit.framework.TestCase.assertEquals;
+
+public class _27Test {
+  private static _27.Solution1 solution1;
+  private static int[] nums;
+
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _27.Solution1();
+  }
+
+  @Test
+  public void test1() {
+    nums = new int[] {3, 2, 2, 3};
+    assertEquals(2, solution1.removeElement(nums, 3));
+  }
+
+  @Test
+  public void test2() {
+    nums = new int[] {2, 2, 3};
+    assertEquals(1, solution1.removeElement(nums, 2));
+  }
+
+  @Test
+  public void test3() {
+    nums = new int[] {1};
+    assertEquals(0, solution1.removeElement(nums, 1));
+  }
+}