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 3 minutes

Notes

not defined yet

Code: 19:26:20 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: 19:26:30 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 CLOSINGS = { '(': ')', '{': '}', '[': ']' };
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (['(', '{', '['].includes(char)) {
            stack.push(char);
        } else if (CLOSINGS[stack.pop()] !== char) {
                return 0;
        }
    }

    return 1;
}

Code: 19:27:07 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 BR = { '(': ')', '{': '}', '[': ']' };
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (['(', '{', '['].includes(char)) {
            stack.push(char);
        } else if (CLOSINGS[stack.pop()] !== char) {
                return 0;
        }
    }

    return 1;
}

Code: 19:27:34 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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (['(', '{', '['].includes(char)) {
            stack.push(char);
        } else if (CLOSINGS[stack.pop()] !== char) {
                return 0;
        }
    }

    return 1;
}

Code: 19:27:44 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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    return 1;
}

Code: 19:28:11 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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    if (stack.length !== 0) {
        return 0;
    }

    return 1;
}

Code: 19:28:17 UTC, js, verify, result: Failed

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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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    return stack.length === 0;
}

Analysis

expand all Example tests

▶

example1
example test 1

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'boolean' found

▶

example2
example test 2

✔

0.072 s

Code: 19:28:35 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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    if (stack.length !== 0) {
        return 0;
    }

    return 1;
}

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.072 s

▶

example2
example test 2

✔

0.072 s

Code: 19:28:38 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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    if (stack.length !== 0) {
        return 0;
    }

    return 1;
}

Analysis

expand all Example tests

▶

example1
example test 1

✔

0.072 s

▶

example2
example test 2

✔

0.068 s

Code: 19:28:41 UTC, js, final, score: 100

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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 BRACKETS = { '(': ')', '{': '}', '[': ']' };
    const OPENINGS = Object.keys(BRACKETS);
    const stack = [];

    for (let i = 0; i < S.length; i++) {
        const char = S[i];

        if (OPENINGS.includes(char)) {
            stack.push(char);
        } else if (BRACKETS[stack.pop()] !== char) {
                return 0;
        }
    }

    if (stack.length !== 0) {
        return 0;
    }

    return 1;
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N)

expand all Example tests

▶

example1
example test 1

✔

0.072 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 + )(

✔

0.080 s

0.068 s

0.072 s

▶

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

✔

0.076 s

0.072 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+

✔

0.080 s