LeetCode----House Robber
2015-09-13 09:55
441 查看
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.
Credits:
Special thanks to @ifanchu for adding this problem and creating all test cases. Also thanks to @ts for
adding additional test cases.
分析:
题意,给定一个所有元素非负数组,从数组中选择元素,要求在不能选择adjacent的元素的情况下使选择的元素总和最大。
这是一道简单的动态规划题,使用f[i]表示选择到下标为i时已选择元素的最大值,nums为给定数组,其状态转移方程为:
f[i] = max{f[i - 1], f[i - 2] + nums[i]}
代码:
优化代码1:
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.
Credits:
Special thanks to @ifanchu for adding this problem and creating all test cases. Also thanks to @ts for
adding additional test cases.
分析:
题意,给定一个所有元素非负数组,从数组中选择元素,要求在不能选择adjacent的元素的情况下使选择的元素总和最大。
这是一道简单的动态规划题,使用f[i]表示选择到下标为i时已选择元素的最大值,nums为给定数组,其状态转移方程为:
f[i] = max{f[i - 1], f[i - 2] + nums[i]}
代码:
class Solution(object): def rob(self, nums): """ :type nums: List[int] :rtype: int """ f = [0] * 100 # record the max money nums_len = len(nums) if nums_len == 0: return 0 elif nums_len == 1: return nums[0] elif nums_len == 2: return nums[0] if nums[0] > nums[1] else nums[1] else: f[0] = nums[0] f[1] = nums[0] if nums[0] > nums[1] else nums[1] for i in range(2, nums_len): f[i] = max(f[i - 1], f[i - 2] + nums[i]) return f[nums_len - 1]
优化代码1:
class Solution(object): def rob(self, nums): """ :type nums: List[int] :rtype: int """ nums_len = len(nums) it1, it2 = 0, 0 for i in range(nums_len): it1 = it2 if it2 > (it1 + nums[i]) else (it1 + nums[i]) it1, it2 = it2, it1 return it2
相关文章推荐
- C++动态规划之最长公子序列实例
- C++动态规划之背包问题解决方法
- C#使用动态规划解决0-1背包问题实例分析
- 动态规划
- leetcode 179 Largest Number
- leetcode 24 Swap Nodes in Pairs
- leetcode 2 Add Two Numbers 方法1
- leetcode 2 Add Two Numbers 方法2
- C++ 动态规划
- [LeetCode]47 Permutations II
- [LeetCode]65 Valid Number
- [LeetCode]123 Best Time to Buy and Sell Stock III
- [LeetCode] String Reorder Distance Apart
- [LeetCode] Sliding Window Maximum
- [LeetCode] Find the k-th Smallest Element in the Union of Two Sorted Arrays
- [LeetCode] Determine If Two Rectangles Overlap
- [LeetCode] A Distance Maximizing Problem
- leetcode_linearList
- leetcode_linearList02
- LeetCode[Day 1] Two Sum 题解