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.

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.

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