4.8 KiB
4.8 KiB
title | id | challengeType |
---|---|---|
Balanced brackets | 594dc6c729e5700999302b45 | 5 |
Description
Determine whether a generated string of brackets is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples:(empty) true
[]
true
][
false
[][]
true
][][
false
[]][[]
false
[[[[]]]]
true
Instructions
Tests
tests:
- text: <code>isBalanced</code> is a function.
testString: assert(typeof isBalanced === 'function', '<code>isBalanced</code> is a function.');
- text: <code>isBalanced("[]")</code> should return true.
testString: assert(isBalanced(testCases[0]), '<code>isBalanced("[]")</code> should return true.');
- text: <code>isBalanced("]][[[][][][]][")</code> should return false.
testString: assert(!isBalanced(testCases[1]), '<code>isBalanced("]][[[][][][]][")</code> should return false.');
- text: <code>isBalanced("[][[[[][][[[]]]]]]")</code> should return true.
testString: assert(isBalanced(testCases[2]), '<code>isBalanced("[][[[[][][[[]]]]]]")</code> should return true.');
- text: <code>isBalanced("][")</code> should return true.
testString: assert(!isBalanced(testCases[3]), '<code>isBalanced("][")</code> should return true.');
- text: <code>isBalanced("[[[]]]][[]")</code> should return true.
testString: assert(!isBalanced(testCases[4]), '<code>isBalanced("[[[]]]][[]")</code> should return true.');
- text: <code>isBalanced("][[]")</code> should return true.
testString: assert(!isBalanced(testCases[5]), '<code>isBalanced("][[]")</code> should return true.');
- text: <code>isBalanced("][[][]][[[]]")</code> should return true.
testString: assert(!isBalanced(testCases[6]), '<code>isBalanced("][[][]][[[]]")</code> should return true.');
- text: <code>isBalanced("[[][]]][")</code> should return true.
testString: assert(!isBalanced(testCases[7]), '<code>isBalanced("[[][]]][")</code> should return true.');
- text: <code>isBalanced("[[[]]][[]]]][][[")</code> should return true.
testString: assert(!isBalanced(testCases[8]), '<code>isBalanced("[[[]]][[]]]][][[")</code> should return true.');
- text: <code>isBalanced("[]][[]]][[[[][]]")</code> should return true.
testString: assert(!isBalanced(testCases[9]), '<code>isBalanced("[]][[]]][[[[][]]")</code> should return true.');
- text: <code>isBalanced("][]][[][")</code> should return true.
testString: assert(!isBalanced(testCases[10]), '<code>isBalanced("][]][[][")</code> should return true.');
- text: <code>isBalanced("[[]][[][]]")</code> should return true.
testString: assert(isBalanced(testCases[11]), '<code>isBalanced("[[]][[][]]")</code> should return true.');
- text: <code>isBalanced("[[]]")</code> should return true.
testString: assert(isBalanced(testCases[12]), '<code>isBalanced("[[]]")</code> should return true.');
- text: <code>isBalanced("]][]][[]][[[")</code> should return true.
testString: assert(!isBalanced(testCases[13]), '<code>isBalanced("]][]][[]][[[")</code> should return true.');
- text: <code>isBalanced("][]][][[")</code> should return true.
testString: assert(!isBalanced(testCases[14]), '<code>isBalanced("][]][][[")</code> should return true.');
- text: <code>isBalanced("][][")</code> should return true.
testString: assert(!isBalanced(testCases[15]), '<code>isBalanced("][][")</code> should return true.');
- text: <code>isBalanced("[[]]][][][[]][")</code> should return true.
testString: assert(!isBalanced(testCases[16]), '<code>isBalanced("[[]]][][][[]][")</code> should return true.');
- text: <code>isBalanced("")</code> should return true.
testString: assert(isBalanced(testCases[17]), '<code>isBalanced("")</code> should return true.');
Challenge Seed
function isBalanced (str) {
// Good luck!
return true;
}
After Test
const testCases = [
'[]',
']][[[][][][]][',
'[][[[[][][[[]]]]]]',
'][',
'[[[]]]][[]',
'][[]',
'][[][]][[[]]',
'[[][]]][',
'[[[]]][[]]]][][[',
'[]][[]]][[[[][]]',
'][]][[][',
'[[]][[][]]',
'[[]]',
']][]][[]][[[',
'][]][][[',
'][][',
'[[]]][][][[]][',
''
];
Solution
function isBalanced (str) {
if (str === '') return true;
let a = str;
let b;
do {
b = a;
a = a.replace(/\[\]/g, '');
} while (a !== b);
return !a;
}