Test results - Codility

Tasks Details

medium

1. MinAbsSumOfTwo

Find the minimal absolute value of a sum of two elements.

Task Score

100%

Correctness

100%

Performance

100%

Let A be a non-empty array consisting of N integers.

The abs sum of two for a pair of indices (P, Q) is the absolute value |A[P] + A[Q]|, for 0 ≤ P ≤ Q < N.

For example, the following array A:

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

has pairs of indices (0, 0), (0, 1), (0, 2), (1, 1), (1, 2), (2, 2).
The abs sum of two for the pair (0, 0) is A[0] + A[0] = |1 + 1| = 2.
The abs sum of two for the pair (0, 1) is A[0] + A[1] = |1 + 4| = 5.
The abs sum of two for the pair (0, 2) is A[0] + A[2] = |1 + (−3)| = 2.
The abs sum of two for the pair (1, 1) is A[1] + A[1] = |4 + 4| = 8.
The abs sum of two for the pair (1, 2) is A[1] + A[2] = |4 + (−3)| = 1.
The abs sum of two for the pair (2, 2) is A[2] + A[2] = |(−3) + (−3)| = 6.

Write a function:

function solution(A);

that, given a non-empty array A consisting of N integers, returns the minimal abs sum of two for any pair of indices in this array.

For example, given the following array A:

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

the function should return 1, as explained above.

Given array A:

A[0] = -8 A[1] = 4 A[2] = 5 A[3] =-10 A[4] = 3

the function should return |(−8) + 5| = 3.

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 [−1,000,000,000..1,000,000,000].

Solution

Programming language used JavaScript

Time spent on task 5 minutes

Notes

not defined yet

Code: 07:34:21 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: 07:34:26 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: 07:34:57 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    console.log(a)
}

Code: 07:34:59 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(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    console.log(A);
}

Analysis

expand all Example tests

▶

example1
first example

✘

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:

[ -3, 1, 4 ]

▶

example2
second example

✘

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:

[ -10, -8, 3, 4, 5 ]

Code: 07:35:10 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let 
}

Code: 07:35:26 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = 
}

Code: 07:35:47 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <=)
}

Code: 07:36:17 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(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const current = Math.abs(A[left] + A[right]);

        if (current < min) {
            min = current;
        }
    }
}

Code: 07:37:06 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = Math.abs(A[left] + A[right]);

        if (current < min) {
            min = current;
        }
    }
}

Code: 07:37:16 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 19 20 21

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

function solution(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];

        if (current < min) {
            min = current;
        }
    }
}

Code: 07:37:47 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 19 20 21 22 23 24 25 26 27

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

function solution(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];

        if (Math.abs(currentSum) < min) {
            min = current;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }
}

Code: 07:37:52 UTC, js, verify, result: Failed

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

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

function solution(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];

        if (Math.abs(currentSum) < min) {
            min = current;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }

    return min;
}

Analysis

expand all Example tests

▶

example1
first example

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

ReferenceError: current is not defined
    at solution (solution.js:18:13)
    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
second example

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.076 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

ReferenceError: current is not defined
    at solution (solution.js:18:13)
    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: 07:38:15 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) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];
        const currentAbs = Math.abs(currentSum);

        if (Math.abs(currentSum) < min) {
            min = current;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }

    return min;
}

Code: 07:38:19 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(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];
        const currentAbs = Math.abs(currentSum);

        if (currentAbs < min) {
            min = currentAbs;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }

    return min;
}

Analysis

expand all Example tests

▶

example1
first example

✔

0.072 s

▶

example2
second example

✔

0.072 s

Code: 07:38:25 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 25 26 27 28 29 30

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

function solution(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];
        const currentAbs = Math.abs(currentSum);

        if (currentAbs < min) {
            min = currentAbs;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }

    return min;
}

Analysis

expand all Example tests

▶

example1
first example

✔

0.072 s

▶

example2
second example

✔

0.072 s

Code: 07:38:27 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 25 26 27 28 29 30

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

function solution(A) {
    const N = A.length;

    A.sort((a, b) => a - b);

    let left = 0;
    let right = N - 1;

    let min = Number.MAX_SAFE_INTEGER;

    while (left <= right) {
        const currentSum = A[left] + A[right];
        const currentAbs = Math.abs(currentSum);

        if (currentAbs < min) {
            min = currentAbs;
        }

        if (currentSum > 0) {
            right--;
        } else {
            left++;
        }
    }

    return min;
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(N * log(N))

expand all Example tests

▶

example1
first example

✔

0.072 s

▶

example2
second example

✔

0.068 s

expand all Correctness tests

▶

extreme_single
sequences of 1 elements

✔

0.068 s

▶

extreme_double
sequences of 2 elements

✔

0.068 s

▶

positive_small
only positive numbers

✔

0.072 s

▶

negative_small
only negative numbers

✔

0.072 s

expand all Performance tests

▶

random_small
random sequence, length = ~1000

✔

0.076 s

▶

random_medium
random sequence, length = ~10,000

✔

0.112 s

▶

arithmetic_medium
arithemtic sequence, length = ~10,000

✔

0.140 s

▶

random_large
random sequence, length = ~100,000

✔

0.208 s

▶

extreme_large
sequence of MAX_INT, length = ~100,000

✔

0.124 s

▶

arithmetic_large
arithmetic sequence, length = ~100,000

✔

0.208 s

▶

constant_distance
constant distance between all elements, length = 100,000

✔

0.208 s