feat: buildTree 문제풀이 추가

Author: JEONGHWANMIN

construct-binary-tree-from-preorder-and-inorder-traversal/hwanmini.js

@@ -0,0 +1,14 @@
+// 시간복잡도: O(n2)
+// 공간복잡도: O(n)
+
+var buildTree = function(preorder, inorder) {
+    if (!preorder.length || !inorder.length) return null;
+
+    const root = new TreeNode(preorder[0]);
+    const mid = inorder.indexOf(root.val);
+
+    root.left = buildTree(preorder.slice(1, mid + 1), inorder.slice(0, mid));
+    root.right = buildTree(preorder.slice(mid + 1), inorder.slice(mid + 1));
+
+    return root;
+};