Find the contiguous subarray within a given array of numbers which has the largest product. The array can contain negative numbers, so you need to account for both maximum and minimum values.

Find the largest magic square within a given matrix. A magic square has equal sums across rows, columns, and both diagonals.

You're given a starting score and a target score. Determine the minimum number of moves (either incrementing or doubling your score) to reach the target.