From 1c9f885fa52047f942bd8627c0ffd835e5a8c629 Mon Sep 17 00:00:00 2001
From: markwang <www.wang61@qq.com>
Date: Thu, 25 Jul 2024 14:50:10 +0800
Subject: [PATCH] =?UTF-8?q?90.=E5=AD=90=E9=9B=86II=E5=A2=9E=E5=8A=A0Go?=
 =?UTF-8?q?=E4=BD=BF=E7=94=A8used=E6=95=B0=E7=BB=84=E8=A7=A3=E6=B3=95?=
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---
 problems/0090.子集II.md | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/problems/0090.子集II.md b/problems/0090.子集II.md
index 03bbd1dc..939ef369 100644
--- a/problems/0090.子集II.md
+++ b/problems/0090.子集II.md
@@ -310,6 +310,43 @@ class Solution:
 ```
 ### Go 
 
+使用used数组
+```Go
+var (
+    result [][]int
+    path []int
+)
+
+func subsetsWithDup(nums []int) [][]int {
+    result = make([][]int, 0)
+    path = make([]int, 0)
+    used := make([]bool, len(nums))
+    sort.Ints(nums) // 去重需要排序
+    backtracing(nums, 0, used)
+    return result
+}
+
+func backtracing(nums []int, startIndex int, used []bool) {
+    tmp := make([]int, len(path))
+    copy(tmp, path)
+    result = append(result, tmp)
+    for i := startIndex; i < len(nums); i++ {
+        // used[i - 1] == true，说明同一树枝candidates[i - 1]使用过
+        // used[i - 1] == false，说明同一树层candidates[i - 1]使用过
+        // 而我们要对同一树层使用过的元素进行跳过
+        if i > 0 && nums[i] == nums[i-1] && used[i-1] == false {
+            continue
+        }
+        path = append(path, nums[i])
+        used[i] = true
+        backtracing(nums, i + 1, used)
+        path = path[:len(path)-1]
+        used[i] = false
+    }
+}
+```
+
+不使用used数组
 ```Go
 var (
     path   []int