Find all unique triplets in an array that sum to zero. You'll need to consider the potential for duplicate numbers and avoid duplicate triplets in your solution.

Determine if a binary tree is height-balanced. A height-balanced tree is defined as one where the difference in height between the left and right subtrees of every node is no more than 1.

Find the length of the longest diagonal segment in a matrix that forms a V-shape. A V-shape is defined by monotonically decreasing values followed by monotonically increasing values along the diagonal.