# Convert BST to Greater Tree LeetCode Solution

Here, We see Convert BST to Greater Tree LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

# List of all LeetCode Solution

## Problem Statement

Given the `root` of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus the sum of all keys greater than the original key in BST.

As a reminder, a binary search tree is a tree that satisfies these constraints:

• The left subtree of a node contains only nodes with keys less than the node’s key.
• The right subtree of a node contains only nodes with keys greater than the node’s key.
• Both the left and right subtrees must also be binary search trees.

Example 1:

Input: root = [4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]
Output: [30,36,21,36,35,26,15,null,null,null,33,null,null,null,8]

Example 2:
Input: root = [0,null,1]
Output: [1,null,1]

## Convert BST to Greater Tree LeetCode SolutionC++

``````class Solution {
public:
TreeNode* convertBST(TreeNode* root) {
int num = 0;
solve(root, num);
return root;
}

void solve(TreeNode *root, int &num)
{
if(root == NULL)
return;
solve(root->right, num);
root->val = num + root->val;
num = root->val;
solve(root->left, num);
}
};```Code language: PHP (php)```

## Convert BST to Greater Tree SolutionJava

``````class Solution {
int sum = 0;
public TreeNode convertBST(TreeNode root) {
if(root==null){
return root;
}
reverseInorder(root);
return root;
}
private void reverseInorder(TreeNode root){
if(root==null){
return;
}
reverseInorder(root.right);
root.val = root.val + sum;
sum = root.val;
reverseInorder(root.left);
return;
}
}```Code language: PHP (php)```

## Convert BST to Greater Tree SolutionJavaScript

``````var convertBST = function(root) {
let sum = 0, prev = 0;
function rec(root){
if(root){
rec(root.right);
sum += root.val;
root.val += prev;
prev = sum;
rec(root.left);
}
}
rec(root);
return root;
}```Code language: JavaScript (javascript)```

## Convert BST to Greater Tree SolutionPython

``````class Solution(object):
def convertBST(self, root):
def dfs(node):
if node:
dfs(node.right)
node.val += dfs.greater_sum
dfs.greater_sum = node.val
dfs(node.left)
dfs.greater_sum = 0
dfs(root)
return root``````
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