2140-solving-questions-with-brainpower.js

/**
 * 2140. Solving Questions With Brainpower
 * https://leetcode.com/problems/solving-questions-with-brainpower/
 * Difficulty: Medium
 *
 * You are given a 0-indexed 2D integer array questions where questions[i] = [pointsi, brainpoweri].
 *
 * The array describes the questions of an exam, where you have to process the questions in order
 * (i.e., starting from question 0) and make a decision whether to solve or skip each question.
 * Solving question i will earn you pointsi points but you will be unable to solve each of the next
 * brainpoweri questions. If you skip question i, you get to make the decision on the next question.
 *
 * For example, given questions = [[3, 2], [4, 3], [4, 4], [2, 5]]:
 * - If question 0 is solved, you will earn 3 points but you will be unable to solve questions
 *   1 and 2.
 * - If instead, question 0 is skipped and question 1 is solved, you will earn 4 points but you
 *   will be unable to solve questions 2 and 3.
 *
 * Return the maximum points you can earn for the exam.
 */

/**
 * @param {number[][]} questions
 * @return {number}
 */
var mostPoints = function(questions) {
  const dp = new Array(questions.length + 1).fill(0);

  for (let i = questions.length - 1; i >= 0; i--) {
    const [points, brainpower] = questions[i];
    const nextAvailable = Math.min(questions.length, i + brainpower + 1);
    dp[i] = Math.max(points + dp[nextAvailable], dp[i + 1]);
  }

  return dp[0];
};