[LeetCode]Construct Binary Tree from Preorder and Inorder Traversal

public class Solution {
public TreeNode buildTree(int[] preorder, int[] inorder) {
int length = preorder.length;
if (length == 0) {
return null;
}
TreeNode root = new TreeNode(preorder[0]);
int i = 0;
for(; i < length; i++) {
if (inorder[i] == root.val) {
break;
}
}
root.left = buildTree(Arrays.copyOfRange(preorder, 1, 1 + i), Arrays.copyOfRange(inorder, 0, i));
root.right = buildTree(Arrays.copyOfRange(preorder, 1 + i, length), Arrays.copyOfRange(inorder, 1 + i, length));
return root;
}
}