문제를 본 날: 2022년 10월 31일
문제를 푼 날: 2022년 11월 1일
https://leetcode.com/problems/house-robber-ii/
You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in a circle. That means the first house is the neighbor of the last one. Meanwhile, adjacent houses have a security system connected, and it will automatically contact the police if two adjacent houses were broken into on the same night.
Given an integer array nums representing the amount of money of each house, return the maximum amount of money you can rob tonight without alerting the police.
Example 1:
Input: nums = [2,3,2]
Output: 3
Explanation: You cannot rob house 1 (money = 2) and then rob house 3 (money = 2), because they are adjacent houses.
Example 2:
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 3:
Input: nums = [1,2,3]
Output: 3
Constraints:
1 <= nums.length <= 1000 <= nums[i] <= 1000[1, 3, 4, 7, 9] 일 때, 맨 앞 1과 맨 뒤 9를 동시에 고를 수 없다.
따라서 우리는 맨 앞을 고른다고 했을 때의 [1, 3, 4, 7] 에 대해서, 그리고 맨 뒤를 고른다고 했을 때의 [3, 4, 7, 9] 에 대해 DP를 수행해서 최댓값을 취할 수 있을 것 같다.
이 아이디어를 그대로 코드로 옮기면 다음과 같다.