LeetCode 1646. Get Maximum in Generated Array

Description

https://leetcode.com/problems/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

Returnthe 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

Explanation

Implement as the problem describes and find the max from the list.

Python Solution

class Solution:
    def getMaximumGenerated(self, n: int) -> int:
        if n < 1:
            return 0
        
        nums = [None for i in range(n + 1)]
        
        nums[0] = 0
        nums[1] = 1
        
        for i in range(0, n + 1):

            
            if 2 <= 2 * i <= n:
                nums[2 * i] = nums[i]
            
            if 2 <= 2 * i + 1 <= n:
                nums[2 * i + 1] = nums[i] + nums[i + 1]
        
        return max(nums)