198. House Robber

[fockspaces]

1. use dp to maintain "the max amount thief can steal at index i"
2. initial state: dp[0] -> only can choose nums[0], dp[1] -> either nums[0] or nums[1]
3. update and get the ans

class Solution:
    def rob(self, nums: List[int]) -> int:
        nums.append(0)
        dp = [0] * (len(nums))
        dp[0] = nums[0]
        dp[1] = max(nums[0], nums[1])
        for i in range(2, len(dp)):
            dp[i] = max(dp[i - 1], dp[i - 2] + nums[i])
        return dp.pop()

[fockspaces]

we can smooth dp without extend its length, if comes to one or two nums length, we just return the maximun elements in list

class Solution:
    def rob(self, nums: List[int]) -> int:
        if len(nums) <= 2:
            return max(nums)
        dp = [0] * len(nums)
        dp[0], dp[1] = nums[0], max(nums[0], nums[1])
        for i in range(2, len(dp)):
            dp[i] = max(dp[i - 1], dp[i - 2] + nums[i])
        return dp.pop()