RRURRH

RRURRH is a six-character command sequence that appears in grid-navigation puzzles and introductory programming tasks. In these contexts, each letter encodes a simple action: R represents moving one unit to the right, U represents moving one unit up, and H denotes a halt or stop instruction. The string is often used as a compact example to test input parsing, command interpretation, and basic path computation.

Origin and usage of the term are informal rather than standardized. It surfaces in puzzle wikis, problem statements, and teaching materials as a concise illustration of how a program or agent should process a sequence of directional and control commands. Because RRURRH is short and deterministic, it is well suited for demonstrating the effects of each command on position and for verifying boundary-handling logic.

Mechanics of interpretation generally assume an initial position on a two-dimensional grid. Interpreting RRURRH from (0,0) yields: R to (1,0), R to (2,0), U to (2,1), R to (3,1), R to (4,1), and H halts the run, leaving the agent at (4,1). If grid boundaries or other rules restrict movement, some steps may be ignored or cause an earlier termination according to the given problem’s constraints.

Variants and related concepts frequently appear in programming exercises. Other sequences may replace H with different controls or omit it entirely, and similar strings are used to compare path outcomes under uniform rules.

See also: command string, directional encoding, grid-based pathfinding.