RosettaCodeData/Task/Balanced-brackets/JavaScript/balanced-brackets-2.js

57 lines
1.3 KiB
JavaScript

console.log("Supplied examples");
var tests = ["", "[]", "][", "[][]", "][][", "[[][]]", "[]][[]"];
for (var test of tests)
{
console.log("The string '" + test + "' is " +
(isStringBalanced(test) ? "" : "not ") + "OK.");
}
console.log();
console.log("Random generated examples");
for (var example = 1; example <= 10; example++)
{
var test = generate(Math.floor(Math.random() * 10) + 1);
console.log("The string '" + test + "' is " +
(isStringBalanced(test) ? "" : "not ") + "OK.");
}
function isStringBalanced(str)
{
var paired = 0;
for (var i = 0; i < str.length && paired >= 0; i++)
{
var c = str[i];
if (c == '[')
paired++;
else if (c == ']')
paired--;
}
return (paired == 0);
}
function generate(n)
{
var opensCount = 0, closesCount = 0;
// Choose at random until n of one type generated
var generated = "";
while (opensCount < n && closesCount < n)
{
switch (Math.floor(Math.random() * 2) + 1)
{
case 1:
opensCount++;
generated += "[";
break;
case 2:
closesCount++;
generated += "]";
break;
default:
break;
}
}
// Now pad with the remaining other brackets
generated +=
opensCount == n ? "]".repeat(n - closesCount) : "[".repeat(n - opensCount);
return generated;
}