How should I practice Obstacle-Aware Return to Origin?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Waymo phone screen problems in FastPrep.

Is Obstacle-Aware Return to Origin associated with Waymo?

FastPrep tags this as a Waymo phone screen coding practice problem when the problem catalog has that company and stage context.

Obstacle-Aware Return to Origin

Waymo● EasyFULLTIMEPHONE SCREEN

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Problem statement

A robot starts at (0,0). Commands U, D, L, and R move one grid cell. Return true only when the robot never enters any coordinate in obstacles and finishes back at (0,0). The origin is never blocked.

Function

returnsSafely(moves: String, obstacles: int[][]) → boolean

Examples

Example 1

moves = "URDL"obstacles = []return = true

The four moves form a safe loop.

Example 2

moves = "URDL"obstacles = [[-1,1]]return = false

The robot enters the blocked cell after U then R.

Example 3

moves = "UUDDR"obstacles = []return = false

The path is safe but finishes one column to the right of the origin.

Constraints

0 <= moves.length <= 10^5 and every character is U, D, L, or R.
0 <= obstacles.length <= 10^5; obstacle coordinates are unique and exclude the origin.