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Author: knockcat

1026-maximum-difference-between-node-and-ancestor/1026-maximum-difference-between-node-and-ancestor.cpp

@@ -0,0 +1,38 @@
+/**
+ * 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:
+    
+    int helper(TreeNode* root, int currMax, int currMin)
+    {
+        if(!root)
+            return currMax - currMin;
+        currMax = max(currMax,root->val);
+        currMin = min(currMin,root->val);
+        
+        int left = helper(root->left,currMax,currMin);
+        int right = helper(root->right,currMax,currMin);
+        
+        return max(left,right);
+    }
+    
+    
+    int maxAncestorDiff(TreeNode* root) {
+        
+        if(!root)
+            return 0;
+        
+        return helper(root,root->val,root->val);
+        
+        
+    }
+};