【DP】198.打家劫舍

题目

法1：DP

Python

class Solution:
    def rob(self, nums: List[int]) -> int:
        if len(nums) == 1:
            return nums[0]
        dp = [-1] * len(nums) # 在nums[0, i]之内偷的最多的钱
        dp[0] = nums[0]
        dp[1] = max(nums[0], nums[1])
        for i in range(2, len(nums)):
            dp[i] = max(dp[i-1], dp[i-2] + nums[i])
            print(f'i={i}, val={dp[i]}')
        
        return dp[len(nums) - 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;
    }
}