Interactive - The puzzle is presented as a computer terminal—it prints a number of initialization messages (such as "Finding the best way through the woods...") before prompting the solver for input with a blinking cursor. Click to revealPressing a key on the keyboard will cause the terminal to respond with either "unknown command" or a snippet of Python code; some only print out one set, while others will alternate between multiple pieces of code. Pressing Enter reboots the terminal.
Technology - The various snippets of Python code obtained from the terminal can be assembled into implementations of eleven algorithms named after computer scientists, each of which solves one of the problems referenced in the initialization messages. For example, DIJKSTRA's algorithm corresponds to "Finding the best way through the woods..." As it turns out, the keys corresponding to the code snippets used in any given algorithm spells the eponym of that algorithm, and typing out that name in the terminal yields the whole algorithm.
Error Correction - The algorithm you are given, however, has a single mistake. The Dijkstra implementation, for example, has unvisited[min_node] < unvisited[node]:, where the < should be a > to properly locate the closest unvisited node.
Marked Elements - The error is localized to a single keypress in the terminal, which provides a letter to be extracted. The final answer can be obtained by ordering these letters using the message printed at the beginning.