Islands / Flood Fill

Given a 2D grid representing an image, a starting pixel, and a new color, perform a flood fill (like a paint bucket tool) to recolor the connected region.

Given a binary grid, find the maximum area of an island (connected group of 1s connected 4-directionally).

Given a 2D grid of '1's (land) and '0's (water), count the number of distinct islands formed by connected land cells.

Given a grid where cells contain fresh oranges, rotten oranges, or are empty, determine the minimum time for all fresh oranges to rot via adjacency spreading.

Given a board of 'X' and 'O', capture all regions of 'O' that are completely surrounded by 'X' (not touching the border).