Balanced brackets: Difference between revisions

</pre>

=={{header|Wren}}==

{{trans|Kotlin}}

<lang ecmascript>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")")

}</lang>

{{out}}

<pre>

Checking examples in task description:

(empty) OK

[] OK

][ NOT OK

[][] OK

][][ NOT OK

[[][]] OK

[]][[] NOT OK

Checking 7 random strings of brackets of length 8:

[][][][[ NOT OK

[[][][]] OK

[[[[]]]] OK

[[]]]][[ NOT OK

]][][[]] NOT OK

][]][[[] NOT OK

[][][[][ NOT OK