How should I practice Path Through an O/X Grid Using Only Right and Down?

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

Is Path Through an O/X Grid Using Only Right and Down associated with Amazon?

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

Path Through an O/X Grid Using Only Right and Down

Amazon● MediumFULLTIMEPHONE SCREEN

Problem statement

Given a rectangular array of strings grid, a zero-based coordinate source = [row, col], and a zero-based coordinate destination = [row, col], return whether the destination is reachable.

The character O is open and X is blocked. From an open cell you may move exactly one cell right or one cell down. A blocked endpoint is unreachable, and a destination above or left of the source is also unreachable.

Function

hasRightDownPath(grid: String[], source: int[], destination: int[]) → boolean

Examples

Example 1

grid = ["OOO","OXO","OOO"]source = [0,0]destination = [2,2]return = true

Move right twice and then down twice while avoiding the center obstacle.

Example 2

grid = ["OX","XO"]source = [0,0]destination = [1,1]return = false

Both first moves enter blocked cells.

Example 3

grid = ["OOO"]source = [0,2]destination = [0,0]return = false

Reaching the destination would require moving left.

Constraints

1 <= grid.length, grid[i].length <= 500.
Every row has the same length, and the grid has at most 250000 cells.
Every cell is O or X.
source and destination each contain exactly two valid grid coordinates.