Medium856 challenge

Author: konstantin

src/medium/856. Score of Parentheses .kt

@@ -0,0 +1,43 @@
+package medium
+
+import StackTopic
+import StringTopic
+import java.util.*
+
+
+/**
+ * 856. Score of Parentheses
+ * https://leetcode.com/problems/score-of-parentheses/
+ *
+Given a balanced parentheses string s, return the score of the string.
+The score of a balanced parentheses string is based on the following rule:
+"()" has score 1.
+AB has score A + B, where A and B are balanced parentheses strings.
+(A) has score 2 * A, where A is a balanced parentheses string.
+ BULLSHIT
+ */
+
+class Medium856 : StringTopic, StackTopic {
+
+    fun scoreOfParentheses(s: String): Int {
+        val stack = Stack<Int>()
+        stack.push(0)
+        for (i in s.indices) {
+            if (s[i] == '(') {
+                stack.push(0)
+            } else {
+                val v = stack.pop()
+                val w = stack.pop()
+                stack.push(w + maxOf(2 * v, 1))
+            }
+        }
+        return stack.pop()
+    }
+}
+
+fun main() {
+    println(Medium856().scoreOfParentheses("()"))
+    println(Medium856().scoreOfParentheses("(())"))
+    println(Medium856().scoreOfParentheses("()()"))
+    println(Medium856().scoreOfParentheses("(()(()))"))
+}