Question
In a platformer game, your character climbs a tower of n ledges starting from the ground (ledge 0). Each dash move ascends exactly 1, 2, or 3 ledges. Return the number of distinct sequences of dash moves that land the character exactly on ledge n. If n is 0 the character is already at the top, so return 1. For example, n = 3 has 4 sequences: 1+1+1, 1+2, 2+1, and 3.
count_dash_routes(n: int) → int[3]out4[5]out13State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.