https://leetcode.com/problems/min-cost-climbing-stairs/submissions/

Solution.kt

class Solution {
    fun minCostClimbingStairs(cost: IntArray): Int {
        val nfloors = cost.size
        val cache = HashMap<Int, Int>()
        fun search(f: Int) : Int {
            if (f >= nfloors) { return 0; } // You've reached the top.
            
            if (!cache.contains(f)) {
                cache[f] = cost[f] +arrayOf(search(f + 1), search(f + 2)).min()!!
            }
            
            return cache[f]!!
        }
 
        return if (nfloors == 1) {
            search(0)
        } else {
            arrayOf(search(0), search(1)).min()!!
        }
               
    }
}