Given an array representing the height of bars, calculate how much water can be trapped between them after rain. Think about finding the maximum height to the left and right of each bar.

Find the minimum sum of a path from the top-left to the bottom-right corner of a grid. You can only move down or right at each step.

Calculate the average of the top five scores for each student given a list of their scores. Return the result as a list of student IDs and their corresponding top-five average.