Time: 1 ms (98.83%), Space: 37.7 MB (76.02%) - LeetHub

Author: hajin-kim

0078-subsets/0078-subsets.kt

@@ -0,0 +1,28 @@
+import java.util.LinkedList
+
+class Solution {
+    private fun subsetsMutable(
+        nums: IntArray,
+        i: Int,
+        now: LinkedList<Int>,
+        result: MutableList<List<Int>>,
+    ) {
+        if (i == nums.size) {
+            @Suppress("UNCHECKED_CAST")
+            result += now.clone() as List<Int>
+            return
+        }
+
+        subsetsMutable(nums, i + 1, now, result)
+        now += nums[i]
+        subsetsMutable(nums, i + 1, now, result)
+        now.removeLast()
+    }
+
+    fun subsets(nums: IntArray): List<List<Int>> {
+        val result = mutableListOf<List<Int>>()
+        subsetsMutable(nums, 0, LinkedList(), result)
+
+        return result
+    }
+}