add q384

README.md

@@ -55,6 +55,7 @@
 * [q54_螺旋矩阵](/src/数组操作/q54_螺旋矩阵)
 * [q73_矩阵置零](/src/数组操作/q73_矩阵置零)
 * [q78_子集](/src/数组操作/q78_子集)
+* [q384_打乱数组](/src/数组操作/q384_打乱数组)
 * [q581_最短无序连续子数组](/src/数组操作/q581_最短无序连续子数组)
 * [q945_使数组唯一的最小增量](/src/数组操作/q945_使数组唯一的最小增量)
 

src/数组操作/q384_打乱数组/Solution.java

@@ -0,0 +1,46 @@
+package 数组操作.q384_打乱数组;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+/**
+ * 洗牌算法 o(n)
+ */
+public class Solution {
+    private int[] array;
+    private int[] original;
+
+    private Random rand = new Random();
+
+    private List<Integer> getArrayCopy() {
+        List<Integer> asList = new ArrayList<>();
+        for (int i = 0; i < array.length; i++) {
+            asList.add(array[i]);
+        }
+        return asList;
+    }
+
+    public Solution(int[] nums) {
+        array = nums;
+        original = nums.clone();
+    }
+
+    public int[] reset() {
+        array = original;
+        original = original.clone();
+        return array;
+    }
+
+    public int[] shuffle() {
+        List<Integer> aux = getArrayCopy();
+
+        for (int i = 0; i < array.length; i++) {
+            int removeIdx = rand.nextInt(aux.size());
+            array[i] = aux.get(removeIdx);
+            aux.remove(removeIdx);
+        }
+
+        return array;
+    }
+}