diff --git "a/problems/0300.\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227.md" "b/problems/0300.\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227.md"
index e8cb0b5f18..01d349496b 100644
--- "a/problems/0300.\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227.md"
+++ "b/problems/0300.\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227.md"
@@ -149,7 +149,7 @@ class Solution:
         if len(nums) <= 1:
             return len(nums)
         dp = [1] * len(nums)
-        result = 0
+        result = 1
         for i in range(1, len(nums)):
             for j in range(0, i):
                 if nums[i] > nums[j]:
diff --git "a/problems/0669.\344\277\256\345\211\252\344\272\214\345\217\211\346\220\234\347\264\242\346\240\221.md" "b/problems/0669.\344\277\256\345\211\252\344\272\214\345\217\211\346\220\234\347\264\242\346\240\221.md"
index 95372d6196..85922a1dd8 100644
--- "a/problems/0669.\344\277\256\345\211\252\344\272\214\345\217\211\346\220\234\347\264\242\346\240\221.md"
+++ "b/problems/0669.\344\277\256\345\211\252\344\272\214\345\217\211\346\220\234\347\264\242\346\240\221.md"
@@ -248,6 +248,8 @@ public:
 
 ## Java
 
+**递归**
+
 ```Java
 class Solution {
     public TreeNode trimBST(TreeNode root, int low, int high) {
@@ -269,6 +271,46 @@ class Solution {
 
 ```
 
+**迭代**
+
+```Java
+class Solution {
+    //iteration
+    public TreeNode trimBST(TreeNode root, int low, int high) {
+        if(root == null)
+            return null;
+        while(root != null && (root.val < low || root.val > high)){
+            if(root.val < low)
+                root = root.right;
+            else
+                root = root.left;
+        }
+
+        TreeNode curr = root;
+        
+        //deal with root's left sub-tree, and deal with the value smaller than low.
+        while(curr != null){
+            while(curr.left != null && curr.left.val < low){
+                curr.left = curr.left.right;
+            }
+            curr = curr.left;
+        }
+        //go back to root;
+        curr = root;
+
+        //deal with root's righg sub-tree, and deal with the value bigger than high.
+        while(curr != null){
+            while(curr.right != null && curr.right.val > high){
+                curr.right = curr.right.left;
+            }
+            curr = curr.right;
+        }
+        return root;
+    }
+}
+
+````
+
 ## Python
 
 递归法（版本一）