Test results - Codility

Tasks Details

easy

1. PermMissingElem

Find the missing element in a given permutation.

Task Score

100%

Correctness

100%

Performance

100%

An array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing.

Your goal is to find that missing element.

Write a function:

function solution(A);

that, given an array A, returns the value of the missing element.

For example, given array A such that:

A[0] = 2 A[1] = 3 A[2] = 1 A[3] = 5

the function should return 4, as it is the missing element.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [0..100,000];

the elements of A are all distinct;

each element of array A is an integer within the range [1..(N + 1)].

Solution

Programming language used JavaScript

Time spent on task 3 minutes

Notes

not defined yet

Code: 05:30:07 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: 05:30:11 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(A) {
    // write your code in JavaScript (Node.js 8.9.4)
}

Code: 05:30:44 UTC, js, verify, result: Failed

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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)
    return A.reduce((pre,cur)=> pre^cur);
}

Analysis

expand all Example tests

▶

example
example test

✘

WRONG ANSWER
got 5 expected 4

0.072 s

WRONG ANSWER, got 5 expected 4

Code: 05:31:25 UTC, js, autosave

show code in pop-up

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: 05:31:43 UTC, js, verify, result: Failed

show code in pop-up

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)
    console.log([new Array(A.length+1).keys()])
}

Analysis

expand all Example tests

▶

example
example test

✘

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, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

[ {} ]

Code: 05:31:48 UTC, js, verify, result: Failed

show code in pop-up

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)
    console.log([...new Array(A.length+1).keys()])
}

Analysis

expand all Example tests

▶

example
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

[ 0, 1, 2, 3, 4 ]

Code: 05:31:54 UTC, js, verify, result: Failed

show code in pop-up

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)
    console.log([...new Array(A.length+2).keys()])
}

Analysis

expand all Example tests

▶

example
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

[ 0, 1, 2, 3, 4, 5 ]

Code: 05:32:00 UTC, js, autosave

show code in pop-up

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)
    console.log([...new Array(A.length+2).keys()].conca)
}

Code: 05:32:11 UTC, js, verify, result: Failed

show code in pop-up

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)
    console.log([...new Array(A.length+2).keys()].concat(A).reduce((pre,cur)=>pre^cur))
}

Analysis

expand all Example tests

▶

example
example test

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

Invalid result type, integer expected, 'undefined' found
Perhaps you are missing a 'return'?

stdout:

Code: 05:32:20 UTC, js, verify, result: Passed

show code in pop-up

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)
    return [...new Array(A.length+2).keys()].concat(A).reduce((pre,cur)=>pre^cur);
}

Analysis

expand all Example tests

▶

example
example test

✔

0.072 s

Code: 05:32:24 UTC, js, verify, result: Passed

show code in pop-up

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)
    return [...new Array(A.length+2).keys()].concat(A).reduce((pre,cur)=>pre^cur);
}

Analysis

expand all Example tests

▶

example
example test

✔

0.084 s

Code: 05:32:26 UTC, js, final, score: 100

show code in pop-up

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)
    return [...new Array(A.length+2).keys()].concat(A).reduce((pre,cur)=>pre^cur);
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

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

expand all Example tests

▶

example
example test

✔

0.072 s

expand all Correctness tests

▶

empty_and_single
empty list and single element

✔

0.068 s

▶

missing_first_or_last
the first or the last element is missing

✔

0.068 s

▶

single
single element

✔

0.072 s

▶

double
two elements

✔

0.072 s

0.068 s

0.072 s

▶

simple
simple test

✔

0.068 s

expand all Performance tests

▶

medium1
medium test, length = ~10,000

✔

0.084 s

▶

medium2
medium test, length = ~10,000

✔

0.084 s

▶

large_range
range sequence, length = ~100,000

✔

0.124 s

0.104 s

▶

large1
large test, length = ~100,000

✔

0.128 s

▶

large2
large test, length = ~100,000

✔

0.108 s