kt: add «2140. Solving Questions With Brainpower»

URL:	https://leetcode.com/problems/solving-questions-with-brainpower/
Signed-off-by: Matej Focko <me@mfocko.xyz>

kt/solving-questions-with-brainpower.kt

@@ -0,0 +1,33 @@
+class Solution {
+    private data class Question(val answered: Long, val skipped: Long) {
+        companion object {
+            private fun getWithOffset(
+                stack: List<Question>,
+                offset: Long,
+            ): Long =
+                (stack.size.toLong() - offset - 1).let { i ->
+                    when {
+                        i < 0 || i >= stack.size.toLong() -> 0
+                        else -> stack[i.toInt()].max
+                    }
+                }
+        }
+
+        val max: Long
+            get() = maxOf(answered, skipped)
+
+        constructor(q: IntArray, stack: List<Question>) : this(
+            answered = q[0].toLong() + getWithOffset(stack, q[1].toLong()),
+            skipped = getWithOffset(stack, 0),
+        ) {}
+    }
+
+    fun mostPoints(questions: Array<IntArray>): Long =
+        mutableListOf<Question>().let { st ->
+            questions.asIterable().reversed().forEach { q ->
+                st.add(Question(q, st))
+            }
+
+            st.last().max
+        }
+}