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

这题有点动态规划的意思，每个数字保存一个结果，然后根据当前的数字取之前的数字进行求和计算即可。

class GetMaximumInGeneratedArray : public Solution {
public:
    void Exec() {

    }
    int getMaximumGenerated(int n) {
        if (n <= 1) {
            return n;
        }
        vector<int> values(n + 1, 0);
        values[1] = 1;
        int maxNum = 1;

        for (int i = 2; i <= n; i++) {
            if (i % 2 == 0) {
                values[i] = values[i / 2];
            } else {
                values[i] = values[i / 2] + values[i / 2 + 1];
            }
            maxNum = std::max(maxNum, values[i]);
        }
        return maxNum;
    }
};