feat: 109_convert_sorted_list_to_binary_search_tree

109_convert_sorted_list_to_binary_search_tree/main.cpp

@@ -0,0 +1,59 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct ListNode {
+    int val;
+    ListNode *next;
+    ListNode() : val(0), next(nullptr) {}
+    ListNode(int x) : val(x), next(nullptr) {}
+    ListNode(int x, ListNode *next) : val(x), next(next) {}
+};
+
+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:
+    TreeNode *sortedListToBST(ListNode *head) {
+        if (!head) return nullptr;
+
+        vector<int> nums;
+
+        ListNode *currentNode = head;
+        while (currentNode) {
+            nums.emplace_back(currentNode->val);
+            currentNode = currentNode->next;
+        }
+
+        TreeNode *root = new TreeNode();
+        appendArrayToNode(nums, root);
+        return root;
+    }
+
+    void appendArrayToNode(vector<int> &nums, TreeNode *root) {
+        int mid = nums.size() / 2;
+        root->val = nums[mid];
+
+        if (nums.size() == 1) return;
+
+        vector<int> leftNums, rightNums;
+        copy(nums.begin(), nums.begin() + mid, back_inserter(leftNums));
+        copy(nums.begin() + mid + 1, nums.end(), back_inserter(rightNums));
+
+        if (!leftNums.empty()) {
+            root->left = new TreeNode();
+            appendArrayToNode(leftNums, root->left);
+        }
+
+        if (!rightNums.empty()) {
+            root->right = new TreeNode();
+            appendArrayToNode(rightNums, root->right);
+        }
+    }
+};