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Number of Islands: connected components on a grid (flood fill).

A grid-traversal classic that tests BFS/DFS flood fill and the visited-marking discipline. The signal is treating the grid as a graph and counting connected components. Here is the answer.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.

A grid-traversal classic that tests BFS/DFS flood fill and the visited-marking discipline. The signal is treating the grid as a graph and counting connected components. Here is the answer.

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