【DP】198.打家劫舍

题目

法1：DP

Python

class Solution:
    def rob(self, nums: List[int]) -> int:
        n = len(nums)
        dp = [0] * n # dp[i]偷到i最大的金额
        dp[0] = nums[0]

        for i in range(1, n):
            if i == 1:
                dp[i] = max(nums[0], nums[1])
            else:
                dp[i] = max(dp[i-2] + nums[i], dp[i-1])
        
        return dp[n-1]

Java

class Solution {
    public int rob(int[] nums) {
        int n = nums.length;
        if (n == 1) {
            return nums[0];
        }
        if (n == 2) {
            return Math.max(nums[0], nums[1]);
        }
        int pre0 = nums[0], pre1 = Math.max(nums[0], nums[1]), max = 0;
        for (int i = 2; i < n; ++i) {
            max = Math.max(pre0 + nums[i], pre1);
            pre0 = pre1;
            pre1 = max;
        }
        return max;
    }
}