How should I practice Count Land Islands?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Roblox onsite interview problems in FastPrep.

Is Count Land Islands associated with Roblox?

FastPrep tags this as a Roblox onsite interview coding practice problem when the problem catalog has that company and stage context.

Count Land Islands

Roblox● MediumFULLTIMEONSITE INTERVIEW

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Problem statement

For this exercise, assume grid is a rectangular map: 1 is land and 0 is water. An island is a maximal group of land cells connected by shared sides (up, down, left or right). Diagonals do not connect islands.

Return the number of islands. Do not change the input. A grid with no cells has zero islands.

Function

countIslands(grid: int[][]) → int

Examples

Example 1

grid = [[1,1,0,0],[0,1,0,1],[1,0,0,1]]return = 3

The upper-left group, lower-left cell and right-hand group are three islands.

Example 2

grid = [[1,0],[0,1]]return = 2

The two land cells touch only diagonally.

Example 3

grid = []return = 0

The map has no rows.

Constraints

0 <= grid.length <= 60.
All rows have the same length c, with 0 <= c <= 60.
Every cell is 0 or 1.