Create 0368-largest-divisible-subset.kt

a93a · web-flow · commit 2a2fb2f15deb · 2024-02-09T11:37:48.000+01:00
diff --git a/kotlin/0368-largest-divisible-subset.kt b/kotlin/0368-largest-divisible-subset.kt
@@ -0,0 +1,59 @@
+// DP top-down tabulation
+class Solution {
+    fun largestDivisibleSubset(nums: IntArray): List<Int> {
+        val n = nums.size
+        nums.sort()
+        val dp = nums
+            .map { listOf(it) }
+            .toTypedArray()
+        var res = listOf<Int>()
+
+        for (i in n - 1 downTo 0) {
+            for (j in i + 1 until n) {
+                if (nums[j] % nums[i] == 0) {
+                    val temp = listOf(nums[i]) + dp[j]
+                    dp[i] = if (temp.size > dp[i].size) temp else dp[i]
+                }
+            }
+
+            res = if (dp[i].size > res.size) dp[i] else res
+        }
+
+        return res
+    }
+}
+
+// recursion + memoization
+class Solution {
+    fun largestDivisibleSubset(nums: IntArray): List<Int> {
+        val n = nums.size
+        nums.sort()
+        val dp = HashMap<Int, List<Int>>()
+
+        fun dfs(i: Int): List<Int> {
+            if (i == n) return listOf()
+            dp[i]?.let { return it }
+
+            var res = listOf(nums[i])
+            for (j in i + 1 until n) {
+                if (nums[j] % nums[i] == 0) {
+                    val temp = listOf(nums[i]) + dfs(j)
+                    if (temp.size > res.size)
+                        res = temp
+                }
+            }
+
+            dp[i] = res
+            return res
+        }
+
+        var res = listOf<Int>()
+        for (i in nums.indices) {
+            val temp = dfs(i)
+            if (temp.size > res.size)
+                res = temp
+        }
+
+        return res
+    }
+}
