count-distinct-elements.md

Count distinct elements

Problem Description

Given an array A of N integers, return the number of unique elements in the array.

Problem Constraints

1 <= N <= 10^5
1 <= A[i] <= 10^9

Input Format

First argument A is an array of integers.

Output Format

Return an integer.

Example Input

Input 1:
A = [3, 4, 3, 6, 6]

Input 2:
A = [3, 3, 3, 9, 0, 1, 0]

Example Output

Output 1:
3

Output 2:
4

Example Explanation

Explanation 1:
The distinct elements of the array are 3, 4 and 6.

Explanation 2:
The distinct elements of the array are 3, 9, 0 and 1.

Output

function countDistinctElements(A) {
    const uniqueElements = new Set(A);
    return uniqueElements.size;
}

// Example Inputs
const A1 = [3, 4, 3, 6, 6];
const A2 = [3, 3, 3, 9, 0, 1, 0];

// Example Outputs
console.log(countDistinctElements(A1)); // Output: 3
console.log(countDistinctElements(A2)); // Output: 4