【当前排名48762】挑战leetcode进入前1w名

李恒道

https://leetcode.cn/problems/maximum-fruits-harvested-after-at-most-k-steps/submissions/596428450/
2062分
刺激

var maxTotalFruits = function (fruits, startPos, k) {
  const cache = new Map();
  for (let index = 0; index < fruits.length; index++) {
    const fruit = fruits[index];
    cache.set(fruit[0], fruit[1]);
  }
  const nextArr = new Array(k + 1);
  const preArr = new Array(k + 1);
  let ans = 0;
  preArr[0] = 0;
  nextArr[0] = 0;
  for (let index = 1; index <= k; index++) {
    nextArr[index] =
      (nextArr[index - 1] ?? 0) + (cache.get(startPos + index) ?? 0);
    preArr[index] =
      (preArr[index - 1] ?? 0) + (cache.get(startPos - index) ?? 0);
  }
  ans = Math.max(nextArr[k], preArr[k]);
  let step = 1;
  while (step * 2 < k) {
    ans = Math.max(ans, preArr[step] + nextArr[k - 2 * step]);
    ans = Math.max(ans, nextArr[step] + preArr[k - 2 * step]);
    step++;
  }
  return ans+(cache.get(startPos)??0);
};