Coding questions · Uber

Print directory tree with indentation

This question evaluates proficiency with representing and traversing hierarchical directory trees and producing depth-based formatted output, testing concepts such as tree traversal, recursion or iterative depth tracking, and string formatting for indentation.

You are given a root directory of a filesystem represented as a tree. Each node is either a directory (can have children) or a file (no children). Print the directory structure starting from the root, using indentation to show depth.

Output format

Print one node per line.
The root is printed with no indentation.
For each depth level below the root, prefix the name with an indentation marker (for example: ⟶ ). Repeating the marker indicates deeper nesting.

Example formatting (depth shown by repeated markers):

dir
⟶ subdir1
⟶ ⟶ file1.ext
⟶ ⟶ subsubdir1
⟶ subdir2
⟶ ⟶ subsubdir2
⟶ ⟶ ⟶ file2.ext

Requirements / assumptions

You may assume the input is already a tree (no cycles).
The children of a directory should be printed in the order they are provided.

Task

Implement a function that, given the root node, prints (or returns as a list of strings) the directory tree in the required format.

Print a Directory Tree

Implement solution(root, indent_marker="-> ") that returns one line per node. root may be a dict with name and children or a [name, children] pair. Children must be emitted in the provided order.

Constraints

The input is already a tree
Files have no children

Hints

Depth-first traversal naturally preserves child order.