Data commit

Task/Balanced-brackets/Wren/balanced-brackets.wren

@@ -0,0 +1,30 @@
+import "random" for Random
+
+var isBalanced = Fn.new { |s|
+    if (s.isEmpty) return true
+    var countLeft = 0 // number of left brackets so far unmatched
+    for (c in s) {
+        if (c == "[") {
+            countLeft = countLeft + 1
+        } else if (countLeft > 0) {
+            countLeft = countLeft - 1
+        } else {
+            return false
+        }
+    }
+    return countLeft == 0
+}
+
+System.print("Checking examples in task description:")
+var brackets = ["", "[]", "][", "[][]", "][][", "[[][]]", "[]][[]"]
+for (b in brackets) {
+    System.write((b != "") ? b : "(empty)")
+    System.print("\t  %(isBalanced.call(b) ? "OK" : "NOT OK")")
+}
+System.print("\nChecking 7 random strings of brackets of length 8:")
+var rand = Random.new()
+for (i in 1..7) {
+    var s = ""
+    for (j in 1..8) s = s + ((rand.int(2) == 0) ? "[" : "]")
+    System.print("%(s)  %(isBalanced.call(s) ? "OK" : "NOT OK")")
+}