Hard Problemsgridoptimization

Largest X Bordered Square

Given a binary matrix of 0s and 1s, find the largest square submatrix whose entire border, all four edges, is made up only of 1s. The interior cells may hold either value.

Do this lesson first: longest common subsequence

The full breakdown and animated table for this problem are still being written. In the meantime, run the four questions on it yourself — that is the whole exercise.