leetcode 198. House Robber

Posted 将者,智、信、仁、勇、严也。

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了leetcode 198. House Robber相关的知识,希望对你有一定的参考价值。

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

Given a list of non-negative integers representing the amount of money of each house, determine the maximum amount of money you can rob tonight without alerting the police.

Example 1:

Input: [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: [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.
class Solution(object):
    def rob(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        # dp
        n = len(nums)
        if n == 0: return 0
        if n == 1: return nums[0]
        dp = [0]*(n+1)
        dp[0], dp[1] = 0, nums[0]        
        for i in xrange(2, n+1):
            dp[i] = max(dp[i-2] + nums[i-1], dp[i-1])
        return dp[n]

 or O(1) space.

class Solution(object):
    def rob(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        # dp
        if not nums: return 0
        if len(nums) == 1: return nums[0]
        a = nums[0]
        b = max(nums[0], nums[1])
        for i in xrange(2, len(nums)):
            b, a = max(a+nums[i], b), b
        return b

 精简版:

class Solution:
    
    def rob(self, nums):        
        last, now = 0, 0        
        for i in nums: last, now = now, max(last + i, now)                
        return now

 

以上是关于leetcode 198. House Robber的主要内容,如果未能解决你的问题,请参考以下文章

leetCode 198. House Robber | 动态规划

LeetCode 198. House Robber

Leetcode 198 House Robber

[leetcode-198-House Robber]

leetcode 198. House Robber

[LeetCode] 198. House Robber