198. House Robber

leetcode.com/problems/house-robber/

House Robber - LeetCode

class Solution {
    
    // dp
    public int rob(int[] nums) {
        int[][] dp = new int[2][nums.length];    
        dp[0][0] = nums[0];
        dp[1][0] = 0;
        
        for(int i=1; i<nums.length; i++) {
            dp[0][i] = dp[1][i-1] + nums[i];
            dp[1][i] = Math.max(dp[0][i-1], dp[1][i-1]);
        }
        return Math.max(dp[0][nums.length-1], dp[1][nums.length-1]);
    }
}

leetcode.com/problems/house-robber/discuss/55695/JAVA-DP-Solution-O(n)-runtime-and-O(1)-space-with-inline-comment

JAVA DP Solution, O(n) runtime and O(1) space, with inline comment - LeetCode Discuss

public int rob(int[] num) {
    int rob = 0; //max monney can get if rob current house
    int notrob = 0; //max money can get if not rob current house
    for(int i=0; i<num.length; i++) {
        int currob = notrob + num[i]; //if rob current value, previous house must not be robbed
        notrob = Math.max(notrob, rob); //if not rob ith house, take the max value of robbed (i-1)th house and not rob (i-1)th house
        rob = currob;
    }
    return Math.max(rob, notrob);
}