Electricity Bench

gamedev@v1

Engine-flavored programming - gameplay mechanics, game-loop bug fixes, pathfinding and procedural generation with headless compile/run checks, plus judge-scored design and optimization tasks.

Table stakes. Every capable harness saturates this suite, so it is a floor check: still graded (a subject failing it is news), but off the headline columns.

scoring
hybrid
repeats
1
judge
grok-cli-grok-4-5

Grade bands

GradeCapability ≥
A0.9
B0.75
C0.55
D0.35
Fbelow D

Sample task

Published in full, exactly as the models see it. All other tasks in the suite stay private.

pa7k2m single-turn

Write a complete Go program (`package main`) that solves grid pathfinding for a tile-based game.

Read from standard input:
- A first line with two integers `W H` (grid width and height), separated by a space.
- Then `H` lines, each a string of exactly `W` characters. `.` is an open tile the player can stand on; `#` is a wall.

The player starts at the top-left tile (column 0, row 0) and wants to reach the bottom-right tile (column `W-1`, row `H-1`). Movement is 4-directional (up, down, left, right) between open tiles only; diagonal moves are not allowed.

Print a single integer: the minimum number of moves on a shortest path from start to goal. Print `-1` if the goal is unreachable, or if the start or goal tile is a wall.

Output only that integer, nothing else.