new soln

Author: shreymehul

1026.MaxAncestorDiff.cs

@@ -0,0 +1,47 @@
+// 1026. Maximum Difference Between Node and Ancestor
+// Given the root of a binary tree, find the maximum value v for which there exist different nodes a and b where v = |a.val - b.val| and a is an ancestor of b.
+// A node a is an ancestor of b if either: any child of a is equal to b or any child of a is an ancestor of b.
+
+// Example 1:
+// Input: root = [8,3,10,1,6,null,14,null,null,4,7,13]
+// Output: 7
+// Explanation: We have various ancestor-node differences, some of which are given below :
+// |8 - 3| = 5
+// |3 - 7| = 4
+// |8 - 1| = 7
+// |10 - 13| = 3
+// Among all possible differences, the maximum value of 7 is obtained by |8 - 1| = 7.
+// Example 2:
+// Input: root = [1,null,2,null,0,3]
+// Output: 3
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     public int val;
+ *     public TreeNode left;
+ *     public TreeNode right;
+ *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+public class Solution {
+    public int MaxAncestorDiff(TreeNode root) {
+        return MaxDiff(root, root.val, root.val);
+    }
+    public int MaxDiff(TreeNode root, int max, int min){
+        if(root == null)
+            return 0;
+        int res = Math.Max(
+            Math.Abs(max-root.val),
+            Math.Abs(min-root.val));
+        max = Math.Max(max, root.val);
+        min = Math.Min(min, root.val);
+        return Math.Max( res,
+                Math.Max(MaxDiff(root.left, max, min),
+                    MaxDiff(root.right, max, min)));
+    }
+
+}