Create 2125-number-of-laser-beams-in-a-bank.kt

Author: a93a

kotlin/2125-number-of-laser-beams-in-a-bank.kt

@@ -0,0 +1,25 @@
+class Solution {
+    fun numberOfBeams(bank: Array<String>): Int {
+        var prev = bank[0].count { it == '1'}
+        var res = 0
+
+        for (i in 1 until bank.size) {
+            val cur = bank[i].count { it == '1'}
+            if (cur > 0) {
+                res += (prev * cur)
+                prev = cur
+            }
+        }
+
+        return res
+    }
+}
+
+// or do it the kotlin way!
+class Solution {
+    fun numberOfBeams(bank: Array<String>) = bank
+        .map { it.count { it == '1' } }
+        .filterNot { it == 0 }
+        .zipWithNext { a, b -> a * b }
+        .sum()
+}