BalanceABinaryTree.txt

/**
 * 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:
    TreeNode* balanceBST(TreeNode* root) 
    {
        vector<int> vec;
        inorder(vec,root);
        return balance(vec,0,vec.size()-1);
        
    }
    void inorder(vector<int> &vec,TreeNode* root)
    {
    if(root==NULL)
        return;
    inorder(vec,root->left);
    vec.push_back(root->val);
    inorder(vec,root->right);
    return;
        
    }
    TreeNode* balance(vector<int> vec,int l,int u)
    {
        if(l>u)
            return NULL;
        int mid=l+(u-l)/2;
        TreeNode* temp=new TreeNode(vec[mid]);
        if(l==u)
            return temp;
        temp->left=balance(vec,l,mid-1);
        temp->right=balance(vec,mid+1,u);
        return temp;
    }
};