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] = 1the 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].
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used JavaScript
Time spent on task 7 minutes
Notes
not defined yet
Code: 15:21:03 UTC,
java,
autosave
Code: 15:22:49 UTC,
js,
autosave
Code: 15:22:59 UTC,
js,
autosave
Code: 15:23:20 UTC,
js,
autosave
Code: 15:23:31 UTC,
js,
autosave
Code: 15:23:40 UTC,
js,
autosave
Code: 15:24:10 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[])
}
}
return 0
}
Code: 15:24:38 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++
}
}
return count;
}
return 0
}
Code: 15:24:48 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0
}
Code: 15:24:52 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
Analysis
Code: 15:25:19 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
Code: 15:25:21 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
User test case 1:
[]
User test case 2:
[1]
User test case 3:
[1, 2, -10, 4, 5]
Analysis
expand all
User tests
1.
0.068 s
OK
function result: 0
function result: 0
1.
0.068 s
OK
function result: 1
function result: 1
1.
0.068 s
OK
function result: 5
function result: 5
Code: 15:25:35 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
User test case 1:
[]
User test case 2:
[1]
User test case 3:
[1, 2, -10, 4, 5]
User test case 4:
[1, 1, 1, 1, 1, 1, 1]
Analysis
expand all
User tests
1.
0.068 s
OK
function result: 0
function result: 0
1.
0.072 s
OK
function result: 1
function result: 1
1.
0.072 s
OK
function result: 5
function result: 5
1.
0.072 s
OK
function result: 1
function result: 1
Code: 15:25:49 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
Code: 15:25:53 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
User test case 1:
[]
User test case 2:
[1]
User test case 3:
[1, 2, -10, 4, 5]
User test case 4:
[1, 1, 1, 1, 1, 1, 1]
User test case 5:
[-1000000, 1000000, 0, 1]
Analysis
Code: 15:26:21 UTC,
js,
autosave
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
Code: 15:26:36 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
User test case 1:
[]
User test case 2:
[1]
User test case 3:
[1, 2, -10, 4, 5]
User test case 4:
[1, 1, 1, 1, 1, 1, 1]
User test case 5:
[-1000000, 1000000, 0, 1]
User test case 6:
[1, 2, 10, 12, 0, 10, 2, 1]
Analysis
expand all
User tests
1.
0.068 s
OK
function result: 0
function result: 0
1.
0.072 s
OK
function result: 1
function result: 1
1.
0.072 s
OK
function result: 5
function result: 5
1.
0.072 s
OK
function result: 1
function result: 1
1.
0.072 s
OK
function result: 4
function result: 4
1.
0.072 s
OK
function result: 5
function result: 5
Code: 15:27:08 UTC,
js,
verify,
result: Passed
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
User test case 1:
[]
User test case 2:
[1]
User test case 3:
[1, 2, -10, 4, 5]
User test case 4:
[1, 1, 1, 1, 1, 1, 1]
User test case 5:
[-1000000, 1000000, 0, 1]
User test case 6:
[1, 2, 10, 12, 0, 10, 2, 1]
Analysis
expand all
User tests
1.
0.072 s
OK
function result: 0
function result: 0
1.
0.072 s
OK
function result: 1
function result: 1
1.
0.072 s
OK
function result: 5
function result: 5
1.
0.072 s
OK
function result: 1
function result: 1
1.
0.072 s
OK
function result: 4
function result: 4
1.
0.072 s
OK
function result: 5
function result: 5
Code: 15:27:11 UTC,
js,
final,
score:
100
// 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)
if (A.length) {
A.sort((a,b) => a-b);
let count = 1;
for (let i = 1; i < A.length; i++) {
if (A[i] !== A[i-1]) {
count++;
}
}
return count;
}
return 0;
}
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(N*log(N)) or O(N)
expand all
Correctness tests
1.
0.068 s
OK
1.
0.072 s
OK
2.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK
1.
0.072 s
OK