198. House Robber

Problem

You are aprofessional robber planning to rob houses along a street. Each house has a certain amout of moeny stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security systems connected and it will automatically contract the police if two adjacent houses were broken into on the same night.

Given an integer array nums representing the amout of money of each house, return the maximum amount of money you can rob tonight without alerting the police.

Example 1:

Input: nums = [1,2,3,1]
Output: 4
Explanation: Rob house 1 (money = 1) and then rob house 3 (money = 3).
Total amount you can rob = 1 + 3 = 4.

Example 2:

Input: nums = [2,7,9,3,1]
Output: 12
Explanation: Rob house 1 (money = 2), rob house 3 (money = 9) and rob house 5 (money = 1).
Total amount you can rob = 2 + 9 + 1 = 12.

Constraints:

• 1 <= nums.length <= 100
• 0 <= nums[i] <= 400

풀이

dp[i] += max(dp[i-3], dp[i-2])

코드

class Solution(object):
    def rob(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        dp = [0] * len(nums)
        for index,num in enumerate(nums) :
            a, b = 0 if index-2 < 0 else dp[index-2], 0 if index -3 < 0 else dp[index-3]
            dp[index] = num + max(a,b)
        return max(dp)