每日题解——2021-8-23

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1646. 获取生成数组中的最大值

给你一个整数 n 。按下述规则生成一个长度为 n + 1 的数组 nums :

nums[0] = 0 nums[1] = 1 当 2 <= 2 * i <= n 时,nums[2 * i] = nums[i] 当 2 <= 2 * i + 1 <= n 时,nums[2 * i + 1] = nums[i] + nums[i + 1] 返回生成数组 nums 中的 最大 值。

 

示例 1:

输入:n = 7
输出:3
解释:根据规则:
  nums[0] = 0
  nums[1] = 1
  nums[(1 * 2) = 2] = nums[1] = 1
  nums[(1 * 2) + 1 = 3] = nums[1] + nums[2] = 1 + 1 = 2
  nums[(2 * 2) = 4] = nums[2] = 1
  nums[(2 * 2) + 1 = 5] = nums[2] + nums[3] = 1 + 2 = 3
  nums[(3 * 2) = 6] = nums[3] = 2
  nums[(3 * 2) + 1 = 7] = nums[3] + nums[4] = 2 + 1 = 3
因此,nums = [0,1,1,2,1,3,2,3],最大值 3

示例 2:

输入:n = 2
输出:1
解释:根据规则,nums[0]、nums[1] 和 nums[2] 之中的最大值是 1

示例 3:

输入:n = 3
输出:2
解释:根据规则,nums[0]、nums[1]、nums[2] 和 nums[3] 之中的最大值是 2

提示:

0 <= n <= 100

1646. Get Maximum in Generated Array

You are given an integer n. An array nums of length n + 1 is generated in the following way:

nums[0] = 0 nums[1] = 1 nums[2 * i] = nums[i] when 2 <= 2 * i <= n nums[2 * i + 1] = nums[i] + nums[i + 1] when 2 <= 2 * i + 1 <= n Return the maximum integer in the array nums​​​.

 

Example 1:

Input: n = 7
Output: 3
Explanation: According to the given rules:
  nums[0] = 0
  nums[1] = 1
  nums[(1 * 2) = 2] = nums[1] = 1
  nums[(1 * 2) + 1 = 3] = nums[1] + nums[2] = 1 + 1 = 2
  nums[(2 * 2) = 4] = nums[2] = 1
  nums[(2 * 2) + 1 = 5] = nums[2] + nums[3] = 1 + 2 = 3
  nums[(3 * 2) = 6] = nums[3] = 2
  nums[(3 * 2) + 1 = 7] = nums[3] + nums[4] = 2 + 1 = 3
Hence, nums = [0,1,1,2,1,3,2,3], and the maximum is 3.

Example 2:

Input: n = 2
Output: 1
Explanation: According to the given rules, the maximum between nums[0], nums[1], and nums[2] is 1.

Example 3:

Input: n = 3
Output: 2
Explanation: According to the given rules, the maximum between nums[0], nums[1], nums[2], and nums[3] is 2.

 

Constraints:

0 <= n <= 100

代码

/**
 * @param {number} n
 * @return {number}
 */
var getMaximumGenerated = function(n) {
    if (n === 0) {
        return 0;
    }
    const nums = new Array(n + 1).fill(0);
    nums[1] = 1;
    for (let i = 2; i <= n; ++i) {
        nums[i] = nums[Math.floor(i / 2)] + i % 2 * nums[Math.floor(i / 2) + 1];
    }
    return Math.max(...nums);
};