198. House Robber

QUESTION:

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.

EXPLANATION:

其实就是一个循环然后求出结果,注意的是preNo的值是之前两个的最大值这个地方。

SOLUTION:

public int rob(int[] nums) {
        if(nums==null || nums.length ==0 ) return 0;
        int preYes = 0;
        int preNo = 0;
        for(int n : nums){
            int temp = preNo;
            preNo = Math.max(preYes,preNo);
            preYes = n + temp;
        }
        return Math.max(preYes,preNo);
    }