Number of Islands | Dataford Interview Questions

How would you find the number of islands in a grid?

Implement the solution for a rectangular grid containing "1" for land and "0" for water. Return the number of connected land regions, where cells connect only horizontally or vertically, not diagonally. The input is a list of equal-length strings, and the output is an integer.

Constraints

0 <= len(grid) <= 300
0 <= len(grid[0]) <= 300 when the grid is non-empty
Each row has the same length
Each cell is either "0" or "1"
Cells connect only horizontally or vertically

Function Signature

def num_islands(grid):

Your question is Number of Islands. Start with the requirements in the Question tab.

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Problem

How would you find the number of islands in a grid?

Constraints

0 <= len(grid) <= 300
0 <= len(grid[0]) <= 300 when the grid is non-empty
Each row has the same length
Each cell is either "0" or "1"
Cells connect only horizontally or vertically

Function Signature

def num_islands(grid):

Your question is Number of Islands. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.