leetcode_gym/_problems/houseRobber2.md

layout, title

layout	title
page	House Robber 2

Do house robber twice with a helper function. First time exclude first element, second exclude last element. Then take max.

Handle corner cases first.

{% highlight python %}

def rob(nums):

# handle edge cases
if not nums: return 0
if len(nums)==1: return nums[0]
if len(nums)==2: return max(nums[0], nums[1])

def robHelper(nums):

    dp = [1] * len(nums)
    dp[0] = nums[0]
    dp[1] = max(nums[0], nums[1])

    for i in range(2, len(nums)):
        dp[i] = max( nums[i] + dp[i-2], dp[i-1] )

    print(dp)

    return dp[-1]

excludeFirst = nums[1:]
excludeLast = nums[:-1]

return max( robHelper(excludeFirst), robHelper(excludeLast)  )

{% endhighlight %}