class Solution:
    def canJump(self, nums: List[int]) -> bool:
        if len(nums) <= 1:
            return True

        max_can_reach_idx = [0 for _ in range(len(nums))]
        for i, num in enumerate(nums):
            if i == 0:
                max_can_reach_idx[0] = num+i
            if i > 0 and max_can_reach_idx[i-1] >= i:
                max_can_reach_idx[i] = max(max_can_reach_idx[i-1], num+i)

        return max_can_reach_idx[-1] > 0

class Solution:
    def canJump(self, nums: List[int]) -> bool:
        max_idx = 0
        for i, num in enumerate(nums):
            if i > max_idx: # can not reach, first 0 > 0 
                return False
            max_idx = max(num+i, max_idx)

        return max_idx >= len(nums)-1 # 4 >= 5-1