House Robber III

Author: piyush6348

House Robber III.cpp

@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+unordered_map<TreeNode*,int> um;
+
+    int rob(TreeNode* root) {
+        if(root==NULL)
+            return 0;
+        if(um.find(root)!=um.end())
+            return (um.find(root)->second);
+        int val=0;
+        if(root->left!=NULL)
+            val+=rob(root->left->left) + rob(root->left->right);
+        if(root->right!=NULL)
+            val+=rob(root->right->left) + rob(root->right->right);
+        int temp=max(val+root->val, rob(root->left)+rob(root->right));
+        
+        um[root]=temp;    
+        return temp;
+    }
+};