refactor 496

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_496.java

@@ -5,9 +5,11 @@
 import java.util.Stack;
 
 /**
- * You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1's elements in the corresponding places of nums2.
-
- The Next Greater Number of a number x in nums1 is the first greater number to its right in nums2. If it does not exist, output -1 for this number.
+ * 496. Next Greater Element I
+ *
+ * You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2.
+ * Find all the next greater numbers for nums1's elements in the corresponding places of nums2.
+ * The Next Greater Number of a number x in nums1 is the first greater number to its right in nums2. If it does not exist, output -1 for this number.
 
  Example 1:
  Input: nums1 = [4,1,2], nums2 = [1,3,4,2].
@@ -16,63 +18,41 @@
  For number 4 in the first array, you cannot find the next greater number for it in the second array, so output -1.
  For number 1 in the first array, the next greater number for it in the second array is 3.
  For number 2 in the first array, there is no next greater number for it in the second array, so output -1.
+
  Example 2:
  Input: nums1 = [2,4], nums2 = [1,2,3,4].
  Output: [3,-1]
  Explanation:
  For number 2 in the first array, the next greater number for it in the second array is 3.
  For number 4 in the first array, there is no next greater number for it in the second array, so output -1.
+
  Note:
  All elements in nums1 and nums2 are unique.
  The length of both nums1 and nums2 would not exceed 1000.
  */
 public class _496 {
 
-    public int[] nextGreaterElement_clever_way(int[] findNums, int[] nums) {
-        Stack<Integer> stack = new Stack();
-        Map<Integer, Integer> map = new HashMap();
-        for (int i = 0; i < nums.length; i++) {
-            while (!stack.isEmpty() && nums[i] > stack.peek()) {
-                map.put(stack.pop(), nums[i]);
+    public static class Solution1 {
+        public int[] nextGreaterElement(int[] findNums, int[] nums) {
+            Stack<Integer> stack = new Stack();
+            Map<Integer, Integer> map = new HashMap();
+            for (int i = 0; i < nums.length; i++) {
+                while (!stack.isEmpty() && nums[i] > stack.peek()) {
+                    map.put(stack.pop(), nums[i]);
+                }
+                stack.push(nums[i]);
             }
-            stack.push(nums[i]);
-        }
-
-        while (!stack.isEmpty()) {
-            map.put(stack.pop(), -1);
-        }
 
-        int[] result = new int[findNums.length];
-        for (int i = 0; i < findNums.length; i++) {
-            result[i] = map.get(findNums[i]);
-        }
-        return result;
-    }
-
-
-    public int[] nextGreaterElement_naive_way(int[] findNums, int[] nums) {
-        int[] result = new int[findNums.length];
-        for (int i = 0; i < findNums.length; i++) {
-            boolean found = false;
-            boolean foundNext = false;
-            for (int j = 0; j < nums.length; j++) {
-                if (findNums[i] != nums[j] && !found) {
-                    continue;
-                } else if (!found) {
-                    found = true;
-                } else {
-                    if (nums[j] > findNums[i]) {
-                        result[i] = nums[j];
-                        foundNext = true;
-                        break;
-                    }
-                }
+            while (!stack.isEmpty()) {
+                map.put(stack.pop(), -1);
             }
-            if (!foundNext) {
-                result[i] = -1;
+
+            int[] result = new int[findNums.length];
+            for (int i = 0; i < findNums.length; i++) {
+                result[i] = map.get(findNums[i]);
             }
+            return result;
         }
-        return result;
     }
 
 }

src/test/java/com/fishercoder/_496Test.java

@@ -8,15 +8,15 @@
 import static org.junit.Assert.assertArrayEquals;
 
 public class _496Test {
-    private static _496 test;
+    private static _496.Solution1 solution1;
     private static int[] findNums;
     private static int[] nums;
     private static int[] expected;
     private static int[] actual;
 
     @BeforeClass
     public static void setup() {
-        test = new _496();
+        solution1 = new _496.Solution1();
     }
 
     @Before
@@ -32,10 +32,7 @@ public void test1() {
         findNums = new int[]{4, 1, 2};
         nums = new int[]{1, 3, 4, 2};
         expected = new int[]{-1, 3, -1};
-        actual = test.nextGreaterElement_naive_way(findNums, nums);
-        assertArrayEquals(expected, actual);
-
-        actual = test.nextGreaterElement_clever_way(findNums, nums);
+        actual = solution1.nextGreaterElement(findNums, nums);
         assertArrayEquals(expected, actual);
     }
 }