refactor 377

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_377.java

@@ -78,19 +78,19 @@ public static class Solution3 {
          */
         public int combinationSum4(int[] nums, int target) {
             Arrays.sort(nums);
-            int[] result = new int[target + 1];
-            for (int i = 1; i < result.length; i++) {
+            int[] dp = new int[target + 1];
+            for (int i = 1; i < dp.length; i++) {
                 for (int num : nums) {
                     if (num > i) {
                         break;
                     } else if (num == i) {
-                        result[i]++;
+                        dp[i]++;
                     } else {
-                        result[i] += result[i - num];
+                        dp[i] += dp[i - num];
                     }
                 }
             }
-            return result[target];
+            return dp[target];
         }
     }
 
@@ -101,7 +101,7 @@ public static class Solution4 {
          * <p>
          * Reference: https://discuss.leetcode.com/topic/52255/java-recursion-solution-using-hashmap-as-memory
          */
-        public static Map<Integer, Integer> map = new HashMap<>();//need to remove public static before submitting on Leetcode as it doesn't reset static variables
+        Map<Integer, Integer> map = new HashMap<>();
 
         public int combinationSum4(int[] nums, int target) {
             if (nums == null || nums.length == 0 || target < 0) {

src/test/java/com/fishercoder/_377Test.java

@@ -14,53 +14,56 @@ public class _377Test {
     private static _377.Solution4 solution4;
     private static int[] nums;
     private static int target;
+    private static int expected;
 
     @BeforeClass
     public static void setup() {
         solution1 = new _377.Solution1();
         solution2 = new _377.Solution2();
         solution3 = new _377.Solution3();
-        solution4 = new _377.Solution4();
     }
 
     @Before
     public void setUp() throws Exception {
         //always have to reset these global variables before using it again
         solution2.count = 0;
-        solution4.map.clear();
+        solution4 = new _377.Solution4();
     }
 
     @Test
     public void test1() {
-        nums = new int[]{1,2,3};
+        nums = new int[]{1, 2, 3};
         target = 4;
-        assertEquals(7, solution1.combinationSum4(nums, target));
-        assertEquals(7, solution2.combinationSum4(nums, target));
-        assertEquals(7, solution3.combinationSum4(nums, target));
-        assertEquals(7, solution4.combinationSum4(nums, target));
+        expected = 7;
+        assertEquals(expected, solution1.combinationSum4(nums, target));
+        assertEquals(expected, solution2.combinationSum4(nums, target));
+        assertEquals(expected, solution3.combinationSum4(nums, target));
+        assertEquals(expected, solution4.combinationSum4(nums, target));
     }
 
     @Test
     public void test2() {
-        nums = new int[]{4,2,1};
+        nums = new int[]{4, 2, 1};
         target = 32;
+        expected = 39882198;
 //        assertEquals(39882198, solution1.combinationSum4(nums, target));//this results in MLE, so comment out
 
-        assertEquals(39882198, solution2.combinationSum4(nums, target));
+        assertEquals(expected, solution2.combinationSum4(nums, target));
 
-        assertEquals(39882198, solution3.combinationSum4(nums, target));
+        assertEquals(expected, solution3.combinationSum4(nums, target));
 
-        assertEquals(39882198, solution4.combinationSum4(nums, target));
+        assertEquals(expected, solution4.combinationSum4(nums, target));
     }
 
     @Test
     public void test3() {
         nums = new int[]{9};
         target = 3;
-        assertEquals(0, solution1.combinationSum4(nums, target));
-        assertEquals(0, solution2.combinationSum4(nums, target));
-        assertEquals(0, solution3.combinationSum4(nums, target));
-        assertEquals(0, solution4.combinationSum4(nums, target));
+        expected = 0;
+        assertEquals(expected, solution1.combinationSum4(nums, target));
+        assertEquals(expected, solution2.combinationSum4(nums, target));
+        assertEquals(expected, solution3.combinationSum4(nums, target));
+        assertEquals(expected, solution4.combinationSum4(nums, target));
     }
 
-}
+}