CODILITY - LESSON 4 - Distinct

PROBLEM:

Write a function

class Solution { public int solution(int[] A); }

that, given a zero-indexed array A consisting of N integers, returns the number of distinct values in array A.

Assume that:

• 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].

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.

Complexity:

• expected worst-case time complexity is O(N*log(N));
• expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Elements of input arrays can be modified.

MY SOLUTION (100% score, time complexity O(N) or O(N*log(N)))

(codility.com click here to see test results)

class Solution { public int solution(int[] A) { int [] newA = A.Distinct().ToArray(); if (A.Length <=0) return 0; else return newA.Length; } }

Taking advantage .NET libraries and the methods already built-in.

PR