You already know how to count islands. You have been doing it since childhood — glance at a map, and your brain instantly groups the landmasses. But here is the thing: your brain is running an algorithm you have never written down. Today, we write it down.
Start easy. The grid below has '1' for land and '0' for water. Tap each distinct island to count them. A click should feel obvious — you just need to find where one island ends and another begins.