Question

Formatted question description: https://leetcode.ca/all/1646.html

 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

Algorithm

Just add up following problem desciption.

Code

Java

public class Get_Maximum_in_Generated_Array {

    public class Solution {
        public int getMaximumGenerated(int n) {
            if (n <= 1) {
                return n;
            }

            int res = 0;

            int[] dp = new int[n + 1];
            dp[0] = 0;
            dp[1] = 1;
            for (int i = 2; i <= n; i++) {
                dp[i] = i % 2 == 0 ? dp[i >> 1] : dp[i >> 1] + dp[(i >> 1) + 1];
                res = Math.max(res, dp[i]);
            }

            return res;
        }
    }

}

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