You're given daily stock prices. Find the maximum profit you can make by buying and selling the stock once. You must buy before you sell.

You're given lists of player scores and ages. Find the highest possible total score of a team, but avoid conflicts where an older player has a lower score than a younger player on the team.

You are given an array representing the prefix XOR of another array. Your task is to reconstruct and return the original array from its prefix XOR representation.