LeetCode - Construct Binary Tree from Preorder and Inorder Traversal

class Solution {
    public TreeNode buildTree(int[] preorder, int[] inorder) {
        return buildTree(preorder, inorder, 0, preorder.length - 1, 0);
    }

    private TreeNode buildTree(int[] preorder, int[] inorder, int start, int end, int rootIndex){
        if(start > end) return null;
        TreeNode root = new TreeNode(preorder[rootIndex]);
        int newRoot = -1;
        for(int i = start; i <= end; i++){
            if(inorder[i] == preorder[rootIndex]){
                newRoot = i;
                break;
            }
        }
        root.left = buildTree(preorder, inorder, start, newRoot - 1, rootIndex + 1);
        root.right = buildTree(preorder, inorder, newRoot + 1, end, rootIndex + newRoot - start + 1);
        return root;
    }
}