From 1a553b01d691478c049fd39e59548f3a71c9f456 Mon Sep 17 00:00:00 2001
From: erdengk <15596570256@163.com>
Date: Wed, 16 Feb 2022 17:43:36 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200491.=E9=80=92=E5=A2=9E?=
 =?UTF-8?q?=E5=AD=90=E5=BA=8F=E5=88=97.md=20Java=E8=A7=A3=E6=B3=95?=
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---
 problems/0491.递增子序列.md | 34 +++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/problems/0491.递增子序列.md b/problems/0491.递增子序列.md
index 6d88119e..298586c7 100644
--- a/problems/0491.递增子序列.md
+++ b/problems/0491.递增子序列.md
@@ -227,7 +227,39 @@ class Solution {
     }
 }
 ```
-
+```java
+//法二：使用map
+class Solution {
+    //结果集合
+    List<List<Integer>> res = new ArrayList<>();
+    //路径集合
+    LinkedList<Integer> path = new LinkedList<>();
+    public List<List<Integer>> findSubsequences(int[] nums) {
+        getSubsequences(nums,0);
+        return res;
+    }
+    private void getSubsequences( int[] nums, int start ) {
+        if(path.size()>1 ){
+            res.add( new ArrayList<>(path) );
+            // 注意这里不要加return，要取树上的节点
+        }
+        HashMap<Integer,Integer> map = new HashMap<>();
+        for(int i=start ;i < nums.length ;i++){
+            if(!path.isEmpty() && nums[i]< path.getLast()){
+                continue;
+            }
+            // 使用过了当前数字
+            if ( map.getOrDefault( nums[i],0 ) >=1 ){
+                continue;
+            }
+            map.put(nums[i],map.getOrDefault( nums[i],0 )+1);
+            path.add( nums[i] );
+            getSubsequences( nums,i+1 );
+            path.removeLast();
+        }
+    }
+}
+```
 
 ### Python