refactor 18

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_18.java

@@ -23,43 +23,44 @@
 
 public class _18 {
 
-    public List<List<Integer>> fourSum(int[] nums, int target) {
-        List<List<Integer>> result = new ArrayList();
-        if (nums == null || nums.length == 0) {
-            return result;
-        }
-        Arrays.sort(nums);
-        for (int i = 0; i < nums.length - 3; i++) {
-            if (i > 0 && nums[i - 1] == nums[i]) {
-                continue;
+    public static class Solution1 {
+        public List<List<Integer>> fourSum(int[] nums, int target) {
+            List<List<Integer>> result = new ArrayList();
+            if (nums == null || nums.length == 0) {
+                return result;
             }
-            for (int j = i + 1; j < nums.length - 2; j++) {
-                if (j > i + 1 && nums[j - 1] == nums[j]) {
+            Arrays.sort(nums);
+            for (int i = 0; i < nums.length - 3; i++) {
+                if (i > 0 && nums[i - 1] == nums[i]) {
                     continue;
                 }
-                int left = j + 1;
-                int right = nums.length - 1;
-                while (left < right) {
-                    int sum = nums[i] + nums[j] + nums[left] + nums[right];
-                    if (sum == target) {
-                        result.add(Arrays.asList(nums[i], nums[j], nums[left], nums[right]));
-                        while (left + 1 < right && nums[left] == nums[left + 1]) {
+                for (int j = i + 1; j < nums.length - 2; j++) {
+                    if (j > i + 1 && nums[j - 1] == nums[j]) {
+                        continue;
+                    }
+                    int left = j + 1;
+                    int right = nums.length - 1;
+                    while (left < right) {
+                        int sum = nums[i] + nums[j] + nums[left] + nums[right];
+                        if (sum == target) {
+                            result.add(Arrays.asList(nums[i], nums[j], nums[left], nums[right]));
+                            while (left + 1 < right && nums[left] == nums[left + 1]) {
+                                left++;
+                            }
+                            while (right - 1 > left && nums[right] == nums[right - 1]) {
+                                right--;
+                            }
                             left++;
-                        }
-                        while (right - 1 > left && nums[right] == nums[right - 1]) {
                             right--;
+                        } else if (sum > target) {
+                            right--;
+                        } else {
+                            left++;
                         }
-                        left++;
-                        right--;
-                    } else if (sum > target) {
-                        right--;
-                    } else {
-                        left++;
                     }
                 }
             }
+            return result;
         }
-        return result;
     }
-
 }

src/test/java/com/fishercoder/_18Test.java

@@ -0,0 +1,23 @@
+package com.fishercoder;
+
+import com.fishercoder.common.utils.CommonUtils;
+import com.fishercoder.solutions._18;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class _18Test {
+    private static _18.Solution1 solution1;
+    private static int[] nums;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _18.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        nums = new int[]{1, 0, -1, 0, -2, 2};
+        CommonUtils.printListList(solution1.fourSum(nums, 0));
+    }
+
+}