refactor 1491

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1491|[Average Salary Excluding the Minimum and Maximum Salary](https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1491.java) | |Easy|Array, Sort|
 |1487|[Making File Names Unique](https://leetcode.com/problems/making-file-names-unique/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1487.java) | |Medium|HashTable, String|
 |1486|[XOR Operation in an Array](https://leetcode.com/problems/xor-operation-in-an-array/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1486.java) | |Medium|Array, Bit Manipulation|
 |1481|[Least Number of Unique Integers after K Removals](https://leetcode.com/problems/least-number-of-unique-integers-after-k-removals/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1481.java) | |Medium|Array, Sort|

src/main/java/com/fishercoder/solutions/_1491.java

@@ -0,0 +1,23 @@
+package com.fishercoder.solutions;
+
+public class _1491 {
+    public static class Solution1 {
+        public double average(int[] salary) {
+            int max = salary[0];
+            int min = salary[0];
+            for (int i = 1; i < salary.length; i++) {
+                max = Math.max(max, salary[i]);
+                min = Math.min(min, salary[i]);
+            }
+            long total = 0;
+            int count = 0;
+            for (int i = 0; i < salary.length; i++) {
+                if (salary[i] != max && salary[i] != min) {
+                    total += salary[i];
+                    count++;
+                }
+            }
+            return (double) total / count;
+        }
+    }
+}

src/test/java/com/fishercoder/_1491Test.java

@@ -0,0 +1,24 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1491;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static junit.framework.TestCase.assertEquals;
+
+public class _1491Test {
+    private static _1491.Solution1 solution1;
+    private static int[] salary;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1491.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        salary = new int[]{4000, 3000, 1000, 2000};
+        assertEquals(2500.0000, solution1.average(salary));
+    }
+
+}