// <copyright file="CombinatoricsCountingTest.cs" company="Math.NET">
// Math.NET Numerics, part of the Math.NET Project
// http://mathnet.opensourcedotnet.info
//
// Copyright (c) 2009 Math.NET
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
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// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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namespace MathNet.Numerics.UnitTests.CombinatoricsTests
{
    using MbUnit.Framework;

    [TestFixture]
    public class CombinatoricsCountingTest
    {
        [Test, Ignore("Depending on Special Functions")]
        [Row(0, 0, 1)]
        [Row(1, 0, 1)]
        [Row(10, 0, 1)]
        [Row(10, 2, 90)]
        [Row(10, 4, 5040)]
        [Row(10, 6, 151200)]
        [Row(10, 9, 3628800)]
        [Row(10, 10, 3628800)]
        public void CanCountVariations(int n, int k, long expected)
        {
            Assert.AreEqual(expected, Combinatorics.Variations(n, k), "Count the number of variations without repetition");
        }

        [Test]
        [Row(0, 1)]
        [Row(10, 11)]
        [Row(0, -1)]
        [Row(1, -1)]
        [Row(-1, 0)]
        [Row(-1, 1)]
        public void OutOfRangeVariationsMustCountToZero(int n, int k)
        {
            Assert.AreEqual(0, Combinatorics.Variations(n, k), "The number of variations without repetition but out of the range must be 0.");
        }

        [Test]
        [Row(0, 0, 1)]
        [Row(1, 0, 1)]
        [Row(10, 0, 1)]
        [Row(10, 2, 100)]
        [Row(10, 4, 10000)]
        [Row(10, 6, 1000000)]
        [Row(10, 9, 1000000000)]
        [Row(10, 10, 10000000000)]
        [Row(10, 11, 100000000000)]
        public void CanCountVariationsWithRepetition(int n, int k, long expected)
        {
            Assert.AreEqual(expected, Combinatorics.VariationsWithRepetition(n, k), "Count the number of variations with repetition");
        }

        [Test]
        [Row(0, 1)]
        [Row(0, -1)]
        [Row(1, -1)]
        [Row(-1, 0)]
        [Row(-1, 1)]
        public void OutOfRangeVariationsWithRepetitionMustCountToZero(int n, int k)
        {
            Assert.AreEqual(0, Combinatorics.VariationsWithRepetition(n, k), "The number of variations with repetition but out of the range must be 0.");
        }
    }
}