Update README.md

Author: assassint2017

README.md

@@ -120,7 +120,7 @@
 102. [Binary Tree Level Order Traversal](https://github.com/assassint2017/leetcode-algorithm/tree/master/Binary%20Tree%20Level%20Order%20Traversal)
 103. [Binary Tree Zigzag Level Order Traversal](https://github.com/assassint2017/leetcode-algorithm/tree/master/Binary%20Tree%20Zigzag%20Level%20Order%20Traversal)
 104. [Maximum Depth of Binary Tree](https://github.com/assassint2017/leetcode-algorithm/tree/master/Maximum%20Depth%20of%20Binary%20Tree)
-105. [Construct Binary Tree from Preorder and Inorder Traversal]()
+105. [Construct Binary Tree from Preorder and Inorder Traversal](https://github.com/assassint2017/leetcode-algorithm/tree/master/Construct%20Binary%20Tree%20from%20Preorder%20and%20Inorder%20Traversal)
 106. [Construct Binary Tree from Inorder and Postorder Traversal]()
 107. [Binary Tree Level Order Traversal II](https://github.com/assassint2017/leetcode-algorithm/tree/master/Binary%20Tree%20Level%20Order%20Traversal%20II)
 108. [Convert Sorted Array to Binary Search Tree]()