110. Balanced Binary Tree

class Solution {
public:
    int getdepth(TreeNode* root){
        if(root==NULL) return 0;
        int left=getdepth(root->left);
        int right=getdepth(root->right);
        return left>right?(left+1):(right+1);
    }
    bool isBalanced(TreeNode* root) {
        if(root==NULL) return true;
        int leftdepth=getdepth(root->left);
        int rightdepth=getdepth(root->right);
        int result=abs(leftdepth-rightdepth);
        if(result>1) return false;
        else 
            return isBalanced(root->left)&&isBalanced(root->right);
    }
};