您当前位置：首页 > php开源 > 综合技术 > leetcode 198 House Robber

leetcode 198 House Robber

来源：程序员人生发布时间：2015-06-04 08:30:22 阅读次数：3336次

今天看了1个华为西安研究院的1个女生代码大神的总结很有感悟，下面这句话送给大家：

只有好的程序员才能写出人类可以理解的代码

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.

the objective function is basically:

dp(i) = max(dp[i⑵] + num[i], dp[i⑴]),

this means the current max is the max of the position i⑵ plus the current num[i], or the max of the previous one i⑴ (cannot including num[i] with i⑴ position, otherwise it will trigger the alarm)

我的解决方案：
这里写图片描述

class Solution {
public:
    int rob(vector<int>& nums)
    {
        if(nums.empty())return 0;

        int length = nums.size();
        vector<int> dp(length,0);

        dp[0] = nums[0];
        dp[1] = max(nums[0],nums[1]);

        for(int i =2; i< length; ++i)
        {
            dp[i] = max(dp[i-2]+nums[i],dp[i-1]);
        }

        return dp[length-1];

    }
};

c语言解决方案：

#define max(a, b) ((a)>(b)?(a):(b))
int rob(int num[], int n) {
    int a = 0;
    int b = 0;

    for (int i=0; i<n; i++)
    {
        if (i%2==0)
        {
            a = max(a+num[i], b);
        }
        else
        {
            b = max(a, b+num[i]);
        }
    }

    return max(a, b);
}

python解决方案：

class Solution:
    # @param num, a list of integer
    # @return an integer
    def rob(self, num):
        # DP O(n) time, O(1) space
        # ik: max include house k
        # ek: max exclude house k, (Note: ek is also the maximum for house 1,...,k⑴)
        # i[k+1]: num[k] + ek #can't include house k
        # e[k+1]: max(ik, ek) # can either include house k or exclude house k
        i, e = 0, 0
        for n in num: #from k⑴ to k
            i, e = n+e, max(i,e)
        return max(i,e)

生活不易，码农辛苦
如果您觉得本网站对您的学习有所帮助,可以手机扫描二维码进行捐赠
程序员人生

------分隔线----------------------------

上一篇 C语言笔记之数据类型（一）

下一篇 shell学习笔记之七（循环）

分享到:

------分隔线----------------------------

为码而活

积分：4237

15粉丝

7关注

栏目热点