Add 897-IncreasingOrderSearchTree.cpp

Author: Rocky-Dewan

Leet_Code/Random Problem/897-IncreasingOrderSearchTree.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:
+    
+    void dfs(TreeNode* node, std::vector<int> &v){
+        if(node == nullptr){return;}
+        dfs(node->left, v);
+        v.push_back(node->val);
+        dfs(node->right, v);
+    }
+    
+    
+    TreeNode* increasingBST(TreeNode* root) {    
+        std::vector<int> v;
+        dfs(root, v);
+        TreeNode* res = nullptr;
+        TreeNode* idx = nullptr;
+        for(int p = 0; p < v.size(); p++){
+            TreeNode* tn = new TreeNode;
+            tn->val = v[p];
+            tn->left = nullptr; tn->right = nullptr;
+            if(p == 0){res = tn; idx = tn;}
+            else{idx->right = tn; idx = tn;}
+        }
+        
+        return res;
+    }
+};