add a solution for 384

fishercoder1534 · fishercoder1534 · commit 4e1241b514f6 · 2021-07-20T14:52:19.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_384.java b/src/main/java/com/fishercoder/solutions/_384.java
@@ -74,5 +74,43 @@ public int[] shuffle() {
             return result;
         }
     }
+
+    public static class Solution2 {
+        /**
+         * credit: https://leetcode.com/problems/shuffle-an-array/discuss/85958/First-Accepted-Solution-Java
+         */
+        private int[] nums;
+        private Random random;
+
+        public Solution2(int[] nums) {
+            this.nums = nums;
+            this.random = new Random();
+        }
+
+        /**
+         * Resets the array to its original configuration and return it.
+         */
+        public int[] reset() {
+            return this.nums;
+        }
+
+        /**
+         * Returns a random shuffling of the array.
+         */
+        public int[] shuffle() {
+            int[] shuffled = this.nums.clone();
+            for (int i = 1; i < nums.length; i++) {
+                int j = random.nextInt(i + 1);
+                swap(shuffled, i, j);
+            }
+            return shuffled;
+        }
+
+        private void swap(int[] shuffled, int i, int j) {
+            int tmp = shuffled[i];
+            shuffled[i] = shuffled[j];
+            shuffled[j] = tmp;
+        }
+    }
 }
 
diff --git a/src/test/java/com/fishercoder/_384Test.java b/src/test/java/com/fishercoder/_384Test.java
@@ -0,0 +1,15 @@
+package com.fishercoder;
+
+import com.fishercoder.common.utils.CommonUtils;
+import com.fishercoder.solutions._384;
+import org.junit.Test;
+
+public class _384Test {
+    private static _384.Solution2 solution2;
+
+    @Test
+    public void test1() {
+        solution2 = new _384.Solution2(new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12});
+        CommonUtils.printArray(solution2.shuffle());
+    }
+}
