#687 · #2140 · Solving Questions With Brainpower(解决智力问题)

You are given a 2-D array questions where questions[i] = [points_i, brainpower_i]. Solving question i earns points_i but forces you to skip the next brainpower_i questions; alternatively you may skip it. Return the maximum points obtainable. Constraints: 1 <= questions.length <= 10^5, 1 <= points_i <= 10^5, 0 <= brainpower_i <= 10^5.