1026. Maximum Difference Between Node and Ancestor

/**
 * 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:
void sol(TreeNode*root, int mx,int mn ,int& diff ){
    if(!root)return ;
        mx=max(root->val,mx);
        mn=min(root->val,mn);
        diff= max(diff,abs(mx-mn));
        sol(root->left,mx,mn,diff);
        sol(root->right,mx,mn,diff);

}
    int maxAncestorDiff(TreeNode* root) {
        int mx=INT_MIN;
        int mn=INT_MAX;
        int diff=-1;
        sol(root,mx,mn,diff);
        return diff;
    }
};