LeetCode 213 on Jeanphilo Blog

LeetCode 213: House Robber II, Splitting the Circle into Two Linear Problems

Tue, 22 Sep 2026 10:00:00 +0800

Problem

Input and Output

Input: an integer array nums, where nums[i] is the money in the i-th house.
The houses form a circle. Adjacent houses cannot both be robbed, so houses 0 and n - 1 cannot both be robbed either.
Output: the maximum amount of money that can be robbed without triggering the alarm.
Constraints: 1 <= nums.length <= 100, 0 <= nums[i] <= 1000.

Examples

Input: nums = [2,3,2]
Output: 3
Explanation: Houses 0 and 2 are adjacent around the circle, so they cannot both be robbed; rob the house containing 3.

Input: nums = [1,2,3,1]
Output: 4
Explanation: We can rob indices 0 and 2, or indices 1 and 3.

Input: nums = [1,2,3]
Output: 3

This tutorial uses Python only and starts with the smallest first-last conflict.