Balanced brackets: Difference between revisions

== {{header|TypeScript}} ==

{{trans|JavaScript}}

<lang javascript>// Balanced brackets

function isStringBalanced(str: string): bool {

var paired = 0;

for (var i = 0; i < str.length && paired >= 0; i++) {

var c = str.charAt(i);

if (c == '[')

paired++;

else if (c == ']')

paired--;

}

return (paired == 0);

}

function generate(n: number): string {

var opensCount = 0, closesCount = 0;

// Choose at random until n of one type generated

var generated: string[] = new Array(); // Works like StringBuilder

while (opensCount < n && closesCount < n) {

if (Math.floor(Math.random() * 2) == 0) {

++opensCount;

generated.push("[");

} else {

++closesCount;

generated.push("]");

}

}

// Now pad with the remaining other brackets

generated.push(opensCount == n ?

"]".repeat(n - closesCount) :

"[".repeat(n - opensCount));

return generated.join("");

}

console.log("Supplied examples");

var tests: string[] = ["", "[]", "][", "[][]", "][][", "[[][]]", "[]][[]"];

for (var test of tests)

console.log(`The string '${test}' is ${(isStringBalanced(test) ? "OK." : "not OK."));

console.log();

console.log("Random generated examples");

for (var example = 0; example < 10; example++) {

var test = generate(Math.floor(Math.random() * 10) + 1);

console.log(`The string '${test}' is ${(isStringBalanced(test) ? "OK." : "not OK.")}`);

}

</lang>

{{out}}

<pre>

Supplied examples

The string '' is OK.

The string '[]' is OK.

The string '][' is not OK.

The string '[][]' is OK.

The string '][][' is not OK.

The string '[[][]]' is OK.

The string '[]][[]' is not OK.

Random generated examples

The string ']]][[[][' is not OK.

The string '][][][[[[]]]' is not OK.

The string ']][[[[]]' is not OK.

The string '][]]]]]][][][][[[[[[' is not OK.

The string '][[[][][[[]]]]' is not OK.

The string '[[[]]]' is OK.

The string ']]]][[[[[]' is not OK.

The string '][[]]]]][[[][[]]][[[' is not OK.

The string ']]]][]][[[[[' is not OK.

The string '[[[[[[]]]]]]' is OK.

</pre>