From f6d0ab40b352bcf58e540b1878f85c57b7a006ef Mon Sep 17 00:00:00 2001
From: pankajm18 <43561999+pankajm18@users.noreply.github.com>
Date: Tue, 27 Oct 2020 23:29:21 +0530
Subject: [PATCH] Create Greater Sum BST

Solution of greater sum BST problem of leetcode.
---
 Greater Sum BST | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Greater Sum BST

diff --git a/Greater Sum BST b/Greater Sum BST
new file mode 100644
index 0000000..122c513
--- /dev/null
+++ b/Greater Sum BST	
@@ -0,0 +1,37 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    vector<TreeNode*>v;
+    vector<int>sum;
+    void inorder(TreeNode* root)
+    {
+        if(root->left!=NULL)
+            inorder(root->left);
+        v.push_back(root);
+        sum.push_back(root->val);
+        if(root->right!=NULL)
+            inorder(root->right);
+    }
+    TreeNode* bstToGst(TreeNode* root) {
+        if(root==NULL)
+            return root;
+        inorder(root);
+        int n=v.size();
+        for(int i=n-2;i>=0;i--)
+            sum[i]+=sum[i+1];
+        for(int i=0;i<n;i++)
+            v[i]->val=sum[i];
+        return root;
+        
+    }
+};