Test results - Codility

Tasks Details

easy

1. Brackets

Determine whether a given string of parentheses (multiple types) is properly nested.

Task Score

100%

Correctness

100%

Performance

100%

A string S consisting of N characters is considered to be properly nested if any of the following conditions is true:

S is empty;

S has the form "(U)" or "[U]" or "{U}" where U is a properly nested string;

S has the form "VW" where V and W are properly nested strings.

For example, the string "{[()()]}" is properly nested but "([)()]" is not.

Write a function:

function solution(S);

that, given a string S consisting of N characters, returns 1 if S is properly nested and 0 otherwise.

For example, given S = "{[()()]}", the function should return 1 and given S = "([)()]", the function should return 0, as explained above.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [0..200,000];

string S is made only of the following characters: '(', '{', '[', ']', '}' and/or ')'.

Solution

Programming language used JavaScript

Time spent on task 7 minutes

Notes

not defined yet

Task timeline

Code: 02:39:15 UTC, java, autosave

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// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(String S) {
        // write your code in Java SE 8
    }
}

Code: 02:39:18 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    // write your code in JavaScript (Node.js 8.9.4)
}

Code: 02:40:03 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        
    }

Code: 02:42:17 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        i
    }

Code: 02:42:29 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i])
    }

Code: 02:42:59 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i])
        }
    }

Code: 02:43:13 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            ) {
            
        }
    }

Code: 02:43:25 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '{' ||
        ) {
            
        }
    }

Code: 02:43:41 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '{' && S[i ] === '{') ||
        ) {
            
        }
    }

Code: 02:44:08 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
        ) {
            
        }
    }

Code: 02:44:25 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
            
        }
    }

Code: 02:44:35 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        }
    }

Code: 02:44:46 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        } else {
            return 0;
        }
    }

Code: 02:45:16 UTC, js, autosave

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        } else {
            return 0;
        }
    }
    if (nested.length === 0) {
        return 1;
    }
}

Code: 02:45:23 UTC, js, verify, result: Passed

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// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        } else {
            return 0;
        }
    }
    if (nested.length === 0) {
        return 1;
    } else {
        return 0;
    }
}

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.072 s

▶

example2
example test 2

✔

0.072 s

Code: 02:45:27 UTC, js, verify, result: Passed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        } else {
            return 0;
        }
    }
    if (nested.length === 0) {
        return 1;
    } else {
        return 0;
    }
}

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.072 s

▶

example2
example test 2

✔

0.072 s

Code: 02:45:30 UTC, js, final, score: 100

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(S) {
    const nested = [];
    for (let i = 0; i < S.length; i++) {
        if (S[i] === '{' || S[i] === '[' || S[i] === '(') {
            nested.push(S[i]);
        } else if (
            (S[i] === '}' && nested[nested.length - 1] === '{') ||
            (S[i] === ']' && nested[nested.length - 1] === '[') ||
            (S[i] === ')' && nested[nested.length - 1] === '(')
        ) {
             nested.pop();
        } else {
            return 0;
        }
    }
    if (nested.length === 0) {
        return 1;
    } else {
        return 0;
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example1
example test 1

✔

0.068 s

▶

example2
example test 2

✔

0.068 s

expand all Correctness tests

▶

negative_match
invalid structures

✔

0.068 s

▶

empty
empty string

✔

0.068 s

▶

simple_grouped
simple grouped positive and negative test, length=22

✔

0.068 s

expand all Performance tests

▶

large1
simple large positive test, 100K ('s followed by 100K )'s + )(

✔

0.084 s

0.068 s

0.076 s

▶

large2
simple large negative test, 10K+1 ('s followed by 10K )'s + )( + ()

✔

0.076 s

0.068 s

▶

large_full_ternary_tree
tree of the form T=(TTT) and depth 11, length=177K+

✔

0.080 s

▶

multiple_full_binary_trees
sequence of full trees of the form T=(TT), depths [1..10..1], with/without some brackets at the end, length=49K+

✔

0.076 s

0.068 s

▶

broad_tree_with_deep_paths
string of the form [TTT...T] of 300 T's, each T being '{{{...}}}' nested 200-fold, length=120K+

✔

0.076 s