Merge pull request #975 from spshinde105/spshinde105-patch-1

Added Solution for LeetCode Problem No. 99

Author: Sirajmolla

LeetCode/99. Recover Binary Search Tree/Solution.java

@@ -0,0 +1,28 @@
+class Solution {
+    TreeNode first=null;
+    TreeNode second=null;
+    TreeNode prev=new TreeNode(Integer.MIN_VALUE);
+    public void recoverTree(TreeNode root) {
+        inorder(root);
+        
+		// swap values
+        int temp=first.val;
+        first.val=second.val;
+        second.val=temp;
+    }
+    private void inorder(TreeNode root){
+        if(root==null) return;
+        inorder(root.left);
+		
+        //mark first node
+        if(first==null && prev.val>root.val)
+            first=prev;
+			
+		// mark second node
+        if(first!=null && prev.val>root.val)
+            second=root;
+        
+        prev=root;
+        inorder(root.right);
+    }
+}