add youtube link for 101

fishercoder1534 · fishercoder1534 · commit 972907f9e0ed · 2019-12-12T09:53:52.000-08:00
diff --git a/README.md b/README.md
@@ -719,7 +719,7 @@ _If you like this project, please leave me a star._ &#9733;
 |104|[Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_104.java)| O(n)|O(h) | |Easy| DFS
 |103|[Binary Tree Zigzag Level Order Traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_103.java)| O(n)|O(h) | |Medium| BFS,DFS
 |102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_102.java)| O(n)|O(h) | |Medium| BFS
-|101|[Symmetric Tree](https://leetcode.com/problems/symmetric-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_101.java)| O(n)|O(h) | |Easy| DFS
+|101|[Symmetric Tree](https://leetcode.com/problems/symmetric-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_101.java)| O(n)|O(h) | [:tv:](https://www.youtube.com/watch?v=F85boSPtfKg)|Easy| DFS
 |100|[Same Tree](https://leetcode.com/problems/same-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_100.java)| O(n)|O(h) | [:tv:](https://www.youtube.com/watch?v=2Pe6e0KbgFI)|Easy| DFS
 |99|[Recover Binary Search Tree](https://leetcode.com/problems/recover-binary-search-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_99.java) | O(?) | O(?) | |Hard |
 |98|[Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_98.java) | O(n) | O(h) | |Medium | DFS/Recursion
