Multi-Source BFS

Given a matrix of heights, find all cells from which water can flow to both the Pacific and Atlantic oceans.

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 grid with walls, gates, and empty rooms, fill each empty room with the distance to its nearest gate using multi-source BFS.

Given a binary matrix, find the distance of each cell to the nearest 0 using multi-source BFS.