LeetCode 149 Max Points on Line - Why Naive Fails

Pick every pair of points. For each pair, count how many other points lie on that line.

There are $O(n^2)$ pairs. For each pair, checking all other points is $O(n)$. Total: $O(n^3)$.

With $n = 300$, that's $300^3 = 27$ million operations. Too slow.

You need a way to avoid rechecking the same line from different pairs.