Leetcode 198 House Robber

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.

动态规划：

数组dp表示到当前房屋处抢的最多的金额，为了防止被发现不能抢相邻的房间。

故dp[i] = max(dp[i-2]+nums[i],dp[i-1])

var rob = function(nums) {
    if (nums.length === 0)
        return 0
    var dp = []
    dp[0] = nums[0]
    dp[1] = Math.max(nums[0],nums[1])
    for (var i=2;i<nums.length;i++)
        dp[i] = Math.max(dp[i-2]+nums[i],dp[i-1])
    return dp[nums.length-1]
}

 优化版本：

前面加上两个元素防治溢出

class Solution(object):
    def rob(self, nums):
        m = [0,0] + nums
        for i in range(2,len(m)):
            m[i] = max(m[i-1],m[i-2]+m[i])
        return m[-1]