Problem URL: Solving questions with brainpower

We will start from index 0, then either take the current element or skip it. If we take the current element, we will move forward to the next element. If we skip the current element, we will move forward to the next element. We will use a hashmap to store the results of the subproblems. Now we will calculate all possible starting with values and return the largest one.

class Solution:
    def mostPoints(self, questions: List[List[int]]) -> int:
        def _mostPoints(i: int, memo: dict) -> int:
            if i >= len(questions):
                return 0
            if i in memo:
                return memo[i]

            points, jump = questions[i][0], questions[i][1]
            memo[i] = max(_mostPoints(i+1, memo), points + _mostPoints(i+jump+1, memo))
            return memo[i]

        return _mostPoints(0, {})

Time complexity: O(n)
Space complexity: O(n)