distinct-in-array.js

// 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)
    let distinct = 0;
    let sorted = A.sort((a, b) => a - b);
    let last;
    
    // console.log(sorted)
    sorted.forEach((n, index) => {
        if (n !== last) {
            distinct++;
        }
        
        last = n;
    })
    
    // console.log(distinct)
    
    return distinct;
}

/*
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].

*/