From b3530189489235f1212b89bd9dba0281154f366c Mon Sep 17 00:00:00 2001
From: ZongqinWang <1722249371@qq.com>
Date: Sun, 5 Jun 2022 14:13:41 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200090.=E5=AD=90=E9=9B=86II.?=
 =?UTF-8?q?md=20Scala=E7=89=88=E6=9C=AC?=
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---
 problems/0090.子集II.md | 57 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/problems/0090.子集II.md b/problems/0090.子集II.md
index 74ce000b..9047a809 100644
--- a/problems/0090.子集II.md
+++ b/problems/0090.子集II.md
@@ -434,6 +434,63 @@ func subsetsWithDup(_ nums: [Int]) -> [[Int]] {
 }
 ```
 
+### Scala
+
+不使用userd数组:
+
+```scala
+object Solution {
+  import scala.collection.mutable
+  def subsetsWithDup(nums: Array[Int]): List[List[Int]] = {
+    var result = mutable.ListBuffer[List[Int]]()
+    var path = mutable.ListBuffer[Int]()
+    var num = nums.sorted // 排序
+
+    def backtracking(startIndex: Int): Unit = {
+      result.append(path.toList)
+      if (startIndex >= num.size){
+        return
+      }
+      for (i <- startIndex until num.size) {
+        // 同一树层重复的元素不进入回溯
+        if (!(i > startIndex && num(i) == num(i - 1))) {
+          path.append(num(i))
+          backtracking(i + 1)
+          path.remove(path.size - 1)
+        }
+      }
+    }
+
+    backtracking(0)
+    result.toList
+  }
+}
+```
+
+使用Set去重:
+```scala
+object Solution {
+  import scala.collection.mutable
+  def subsetsWithDup(nums: Array[Int]): List[List[Int]] = {
+    var result = mutable.Set[List[Int]]()
+    var num = nums.sorted
+    def backtracking(path: mutable.ListBuffer[Int], startIndex: Int): Unit = {
+      if (startIndex == num.length) {
+        result.add(path.toList)
+        return
+      }
+      path.append(num(startIndex))
+      backtracking(path, startIndex + 1)  // 选择
+      path.remove(path.size - 1)
+      backtracking(path, startIndex + 1)  // 不选择
+    }
+
+    backtracking(mutable.ListBuffer[Int](), 0)
+
+    result.toList
+  }
+}
+```
 
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 <div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>