fix readme

Author: yennanliu

README.md

@@ -956,8 +956,7 @@
 199| [Binary Tree Right Side View](https://leetcode.com/problems/binary-tree-right-side-view/) | [Python](./leetcode_python/Depth-First-Search/binary-tree-right-side-view.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/BinaryTreeRightSideView.java)| _O(n)_     | _O(h)_ | Medium  |`good basic`, `dfs`, `bfs`,`apple`,`amazon`, `fb`, LC 102| OK*** (6) 
 200| [Number of Islands](https://leetcode.com/problems/number-of-islands/) | [Python](./leetcode_python/Depth-First-Search/number-of-islands.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/NumberOfIslands.java) | _O(m * n)_ | _O(m * n)_| Medium |Curated Top 75, `bfs`, `dfs`,`good basic`,check `# 694, 711 Number of Distinct Islands`,`apple`, `Goldman Sachs`,`google`,`amazon`,`fb`| OK****** (6)
 236 | [Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/) | [Python](./leetcode_python/Depth-First-Search/lowest-common-ancestor-of-a-binary-tree.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/LowestCommonAncestorOfABinaryTree.java) | _O(n)_ | _O(h)_ | Medium | `trick`,EPI, `LCA`,check `235 Lowest Common Ancestor of a Binary Search Tree`,`apple`,`amazon`,`linkedin`,`fb` | AGAIN************* (9)
-247| [Strobogrammatic Number II](https://leetcode.com/problems/strobogrammatic-number-ii/) |  [Python](./leetcode_python/Depth-First-Search/strobogrammatic-number-ii.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/StrobogrammaticNumber2.java)
- | _O(n^2 * 5^(n/2))_ | _O(n)_ | Medium |🔒,check `#246 Strobogrammatic Number`,`good trick`, `google`,`fb`| AGAIN********  (5)
+247| [Strobogrammatic Number II](https://leetcode.com/problems/strobogrammatic-number-ii/) |  [Python](./leetcode_python/Depth-First-Search/strobogrammatic-number-ii.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/StrobogrammaticNumber2.java)| _O(n^2 * 5^(n/2))_ | _O(n)_ | Medium |🔒,check `#246 Strobogrammatic Number`,`good trick`, `google`,`fb`| AGAIN********  (5)
 250| [Count Univalue Subtrees](https://leetcode.com/problems/count-univalue-subtrees) | [Python](./leetcode_python/Depth-First-Search/count-univalue-subtrees.py)  | _O(n)_ | _O(h)_ | Medium      |🔒| AGAIN (not start)
 257| [Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/) | [Python](./leetcode_python/Depth-First-Search/binary-tree-paths.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/DFS/BinaryTreePaths.java)  | _O(n * h)_ | _O(h)_ | Easy | good basic,`apple`, `google`, `amazon`, `fb`, iterative, dfs, LC 112, 113| AGAIN********* (MUST) (7)
 332| [Reconstruct Itinerary](https://leetcode.com/problems/reconstruct-itinerary/) | [Python](./leetcode_python/Depth-First-Search/reconstruct-itinerary.py)  | _O(t! / (n1! * n2! * ... nk!))_ | _O(t)_ | Medium  |`yelp`, `google`| AGAIN* (3) (not start)