Test results - Codility

Tasks Details

easy

1. PermCheck

Check whether array A is a permutation.

Task Score

100%

Correctness

100%

Performance

100%

A non-empty array A consisting of N integers is given.

A permutation is a sequence containing each element from 1 to N once, and only once.

For example, array A such that:

A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2

is a permutation, but array A such that:

A[0] = 4 A[1] = 1 A[2] = 3

is not a permutation, because value 2 is missing.

The goal is to check whether array A is a permutation.

Write a function:

function solution(A);

that, given an array A, returns 1 if array A is a permutation and 0 if it is not.

For example, given array A such that:

A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2

the function should return 1.

Given array A such that:

A[0] = 4 A[1] = 1 A[2] = 3

the function should return 0.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [1..100,000];

each element of array A is an integer within the range [1..1,000,000,000].

Solution

Programming language used JavaScript

Time spent on task 3 minutes

Notes

not defined yet

Code: 22:30:23 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(int[] A) {
        // write your code in Java SE 8
    }
}

Code: 22:30:26 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(A) {
    // write your code in JavaScript (Node.js 8.9.4)
}

Code: 22:30:33 UTC, js, autosave

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1 2 3 4 5 6 7

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

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

Code: 22:30:55 UTC, js, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = 
    
    let sum = (l * (l + 1)) / 2;

    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Code: 22:31:24 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l set.size())
    
    let sum = (l * (l + 1)) / 2;

    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Code: 22:31:37 UTC, js, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size()) {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;

    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Code: 22:31:42 UTC, js, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size()) {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

TypeError: set.size is not a function
    at solution (solution.js:9:19)
    at solutionWrapper (/tmp/exec.js:402:28)
    at Promise.resolve.then (/tmp/exec.js:428:24)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

TypeError: set.size is not a function
    at solution (solution.js:9:19)
    at solutionWrapper (/tmp/exec.js:402:28)
    at Promise.resolve.then (/tmp/exec.js:428:24)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

Code: 22:32:15 UTC, js, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size()) {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

TypeError: set.size is not a function
    at solution (solution.js:9:19)
    at solutionWrapper (/tmp/exec.js:402:28)
    at Promise.resolve.then (/tmp/exec.js:428:24)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

TypeError: set.size is not a function
    at solution (solution.js:9:19)
    at solutionWrapper (/tmp/exec.js:402:28)
    at Promise.resolve.then (/tmp/exec.js:428:24)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

Code: 22:32:37 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Code: 22:32:38 UTC, js, verify, result: Failed

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis

expand all Example tests

▶

example1
the first example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.116 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

solution.js:9
    if (l !== set.size {
                       ^

SyntaxError: Unexpected token {
    at createScript (vm.js:80:10)
    at Object.runInNewContext (vm.js:135:10)
    at getSolution (/tmp/exec.js:392:29)
    at Promise.resolve.then (/tmp/exec.js:426:34)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

▶

example2
the second example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.120 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

solution.js:9
    if (l !== set.size {
                       ^

SyntaxError: Unexpected token {
    at createScript (vm.js:80:10)
    at Object.runInNewContext (vm.js:135:10)
    at getSolution (/tmp/exec.js:392:29)
    at Promise.resolve.then (/tmp/exec.js:426:34)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)
    at Function.Module.runMain (module.js:686:11)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

Code: 22:32:46 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

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);
    
    if (l !== set.size) {
        return 0
    }
    
    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.072 s

▶

example2
the second example test

✔

0.068 s

Code: 22:33:08 UTC, js, autosave

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);

    if (l !== set.size) {
        return 0;
    }

    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Code: 22:33:09 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

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);

    if (l !== set.size) {
        return 0;
    }

    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis

expand all Example tests

▶

example1
the first example test

✔

0.072 s

▶

example2
the second example test

✔

0.072 s

Code: 22:33:11 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

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

function solution(A) {
    // write your code in JavaScript (Node.js 8.9.4)
    const l = A.length;
    const set = new Set(A);

    if (l !== set.size) {
        return 0;
    }

    let sum = (l * (l + 1)) / 2;
    for (const a of A) {
        sum -= a;
    }
    return sum === 0 ? 1 : 0;
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N) or O(N * log(N))

expand all Example tests

▶

example1
the first example test

✔

0.068 s

▶

example2
the second example test

✔

0.068 s

expand all Correctness tests

▶

extreme_min_max
single element with minimal/maximal value

✔

0.072 s

▶

single
single element

✔

0.076 s

0.072 s

▶

double
two elements

✔

0.072 s

0.068 s

▶

antiSum1
total sum is correct, but it is not a permutation, N <= 10

✔

0.072 s

0.068 s

▶

small_permutation
permutation + one element occurs twice, N = ~100

✔

0.072 s

0.068 s

▶

permutations_of_ranges
permutations of sets like [2..100] for which the anwsers should be false

✔

0.068 s

0.072 s

expand all Performance tests

▶

medium_permutation
permutation + few elements occur twice, N = ~10,000

✔

0.092 s

▶

antiSum2
total sum is correct, but it is not a permutation, N = ~100,000

✔

0.140 s

▶

large_not_permutation
permutation + one element occurs three times, N = ~100,000

✔

0.136 s

0.140 s

▶

large_range
sequence 1, 2, ..., N, N = ~100,000

✔

0.140 s

0.144 s

▶

extreme_values
all the same values, N = ~100,000

✔

0.068 s

0.120 s

0.068 s

▶

various_permutations
all sequences are permutations

✔

0.068 s

0.092 s

0.148 s