[Hacker Rank]: Project Euler #1: Multiples of 3 and 5 solved ✓ #13

Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,29 @@
	namespace algorithm_exercises_csharp.hackerrank.prohecteuler;

	[TestClass]
	public class Euler001Test
	{
	public class Euler001TestCase {
	public int a; public int b; public int n; public int answer;
	}

	// dotnet_style_readonly_field = true
	private static readonly Euler001TestCase[] tests = [
	new() { a = 3, b = 5, n = 10, answer = 23},
	new() { a = 3, b = 5, n = 100, answer = 2318},
	new() { a = 3, b = 5, n = 1000, answer = 233168},

	];

	[TestMethod]
	public void Euler001ProblemTest()
	{
	int result;

	foreach (Euler001TestCase test in tests) {
	result = Euler001Problem.Euler001(test.a, test.b, test.n);
	Assert.AreEqual(test.answer, result);
	}
	}
	}

Show comments View file Open in desktop

Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,36 @@
	namespace algorithm_exercises_csharp.hackerrank.prohecteuler;

	using System.Diagnostics.CodeAnalysis;

	public class Euler001Problem
	{
	[ExcludeFromCodeCoverage]
	protected Euler001Problem() {}

	public static int SuOfArithmeticProgression(int n, int d) {
	int new_n = n / d;

	return new_n * (1 + new_n) * d / 2;
	}

	public static int GCD(int u, int v)
	{
	if (v != 0)
	{
	return GCD(v, u % v);
	}
	return u;
	}

	// Function to find the sum of all multiples of a and b below n
	public static int Euler001(int a, int b, int n)
	{
	// Since, we need the sum of multiples less than N
	int new_n = n - 1;
	int lcm = a * b / GCD(a, b);

	return SuOfArithmeticProgression(new_n, a) +
	SuOfArithmeticProgression(new_n, b) -
	SuOfArithmeticProgression(new_n, lcm);
	}
	}

Navigation Menu