198.house-robber.kt

/*
 * @lc app=leetcode id=198 lang=kotlin
 *
 * [198] House Robber
 *
 * https://leetcode.com/problems/house-robber/description/
 *
 * algorithms
 * Easy (41.23%)
 * Likes:    2925
 * Dislikes: 92
 * Total Accepted:    358.6K
 * Total Submissions: 869.1K
 * Testcase Example:  '[1,2,3,1]'
 *
 * 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.
 * 
 * Example 1:
 * 
 * 
 * Input: [1,2,3,1]
 * Output: 4
 * Explanation: Rob house 1 (money = 1) and then rob house 3 (money =
 * 3).
 * Total amount you can rob = 1 + 3 = 4.
 * 
 * Example 2:
 * 
 * 
 * Input: [2,7,9,3,1]
 * Output: 12
 * Explanation: Rob house 1 (money = 2), rob house 3 (money = 9) and rob house
 * 5 (money = 1).
 * Total amount you can rob = 2 + 9 + 1 = 12.
 * 
 * 
 */
class Solution {
    fun rob(nums: IntArray): Int {
        if (nums.size == 0) return 0
        if (nums.size == 1) return nums[0]

        var l = Math.max(nums[0], nums[1])
        var ll = nums[0]

        for (i in 2 until nums.size) {
            val temp = l
            l = Math.max(l, ll+nums[i])
            ll = temp
        }
        return l     
    }
}