AI solution for JavaScript Coding Question on BFE.dev
89. Next Right Sibling

Here's a possible solution in JavaScript:

function getNextRightSibling(target) {
  // Traverse the tree using depth first search
  let node = target;
  while (node.parentNode) {
    // Check if the node has a next sibling
    let sibling = node.nextSibling;
    while (sibling) {
      if (sibling.nodeType === Node.ELEMENT_NODE) {
        // Found the next right sibling element node
        return sibling;
      }
      sibling = sibling.nextSibling;
    }
    // No right sibling, continue with parent node
    node = node.parentNode;
  }
  // Target is the last element in the tree, return null
  return null;
}

This solution works by traversing the DOM tree using depth first search, starting at the target element's parent node and going up to the root node. At each level, it checks if the current node has a next sibling element node, and returns it if found. If no next sibling is found, it continues with the parent node. If the target element is the last element in the tree, it returns null.

Time complexity: The worst case scenario is when the target element is the last element in the tree, and we need to traverse the entire tree to find it. In this case, the time cost is O(n), where n is the number of elements in the tree.

Space complexity: The only extra space used by the function is the stack memory used during the depth first search traversal. In the worst case, when the tree is a straight line, the depth of the recursion is equal to the number of elements in the tree, so the space cost is also O(n). However, in practice, most trees are not straight lines, so the space cost is usually much smaller.