Test results - Codility

Tasks Details

easy

1. Distinct

Compute number of distinct values in an array.

Task Score

100%

Correctness

100%

Performance

100%

Write a function

function solution(A);

that, given an array A consisting of N integers, returns the number of distinct values in array A.

For example, given array A consisting of six elements such that:

A[0] = 2 A[1] = 1 A[2] = 1 A[3] = 2 A[4] = 3 A[5] = 1

the function should return 3, because there are 3 distinct values appearing in array A, namely 1, 2 and 3.

Write an efficient algorithm for the following assumptions:

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

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

Solution

Programming language used JavaScript

Time spent on task 3 minutes

Notes

not defined yet

Task timeline

Code: 11:05:43 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: 11:06:13 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(A) {
    // write your code in JavaScript (Node.js 8.9.4)
}

Code: 11:06:44 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)
    for
}

Code: 11:07:05 UTC, js, autosave

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1 2 3 4 5 6 7 8 9 10

// 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)
    count = new Object();
    for (let i = 0; i< n; i++){
        if 
    }
}

Code: 11:07:35 UTC, js, autosave

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

// 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)
    count = new Object();
    for (let i = 0; i< n; i++){
        count[A[i]] = 1;
    }
    Object.keys(obj).length

}

Code: 11:07:44 UTC, js, verify, result: Failed

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

// 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)
    count = new Object();
    for (let i = 0; i< n; i++){
        count[A[i]] = 1;
    }
    return(Object.keys(count).length)

}

Analysis

expand all Example tests

▶

example1
example test, positive answer

✘

RUNTIME ERROR
tested program terminated with exit code 1

0.072 s

RUNTIME ERROR, tested program terminated with exit code 1

stderr:

ReferenceError: n is not defined
    at solution (solution.js:7:24)
    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: 11:07:55 UTC, js, verify, result: Passed

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

// 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)
    count = new Object();
    for (let i = 0; i< A.length; i++){
        count[A[i]] = 1;
    }
    return(Object.keys(count).length)

}

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.068 s

Code: 11:08:01 UTC, js, verify, result: Passed

show code in pop-up

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

// 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 count = new Object();
    for (let i = 0; i< A.length; i++){
        count[A[i]] = 1;
    }
    return(Object.keys(count).length)

}

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.072 s

Code: 11:08:13 UTC, js, verify, result: Passed

show code in pop-up

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

// 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 count = new Object();
    for (let i = 0; i< A.length; i++){
        count[A[i]] = 1;
    }
    return(Object.keys(count).length)

}

Analysis

expand all Example tests

▶

example1
example test, positive answer

✔

0.072 s

Code: 11:08:17 UTC, js, final, score: 100

show code in pop-up

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

// 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 count = new Object();
    for (let i = 0; i< A.length; i++){
        count[A[i]] = 1;
    }
    return(Object.keys(count).length)

}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

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

expand all Example tests

▶

example1
example test, positive answer

✔

0.068 s

expand all Correctness tests

▶

extreme_empty
empty sequence

✔

0.068 s

▶

extreme_single
sequence of one element

✔

0.068 s

▶

extreme_two_elems
sequence of three distinct elements

✔

0.068 s

▶

extreme_one_value
sequence of 10 equal elements

✔

0.068 s

▶

extreme_negative
sequence of negative elements, length=5

✔

0.068 s

▶

extreme_big_values
sequence with big values, length=5

✔

0.068 s

▶

medium1
chaotic sequence of value sfrom [0..1K], length=100

✔

0.068 s

▶

medium2
chaotic sequence of value sfrom [0..1K], length=200

✔

0.068 s

▶

medium3
chaotic sequence of values from [0..10], length=200

✔

0.068 s

expand all Performance tests

▶

large1
chaotic sequence of values from [0..100K], length=10K

✔

0.088 s

▶

large_random1
chaotic sequence of values from [-1M..1M], length=100K

✔

0.192 s

▶

large_random2
another chaotic sequence of values from [-1M..1M], length=100K

✔

0.196 s