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# Joe-Davidson1802's solution

## to Twelve Days in the C# Track

Published at Jul 13 2018 · 0 comments
Instructions
Test suite
Solution

#### Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

Output the lyrics to 'The Twelve Days of Christmas'.

On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.
On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.
On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the seventh day of Christmas my true love gave to me, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the eighth day of Christmas my true love gave to me, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the ninth day of Christmas my true love gave to me, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the tenth day of Christmas my true love gave to me, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the eleventh day of Christmas my true love gave to me, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.
On the twelfth day of Christmas my true love gave to me, twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.

## Hints

• Try to capture the structure of the song in your code, where you build up the song by composing its parts.

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

### TwelveDaysTest.cs

// This file was auto-generated based on version 1.1.0 of the canonical data.

using Xunit;

public class TwelveDaysTest
{
[Fact]
public void First_day_a_partridge_in_a_pear_tree()
{
var expected = "On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(1));
}

[Fact(Skip = "Remove to run test")]
public void Second_day_two_turtle_doves()
{
var expected = "On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(2));
}

[Fact(Skip = "Remove to run test")]
public void Third_day_three_french_hens()
{
var expected = "On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(3));
}

[Fact(Skip = "Remove to run test")]
public void Fourth_day_four_calling_birds()
{
var expected = "On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(4));
}

[Fact(Skip = "Remove to run test")]
public void Fifth_day_five_gold_rings()
{
var expected = "On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(5));
}

[Fact(Skip = "Remove to run test")]
public void Sixth_day_six_geese_a_laying()
{
var expected = "On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(6));
}

[Fact(Skip = "Remove to run test")]
public void Seventh_day_seven_swans_a_swimming()
{
var expected = "On the seventh day of Christmas my true love gave to me, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(7));
}

[Fact(Skip = "Remove to run test")]
public void Eighth_day_eight_maids_a_milking()
{
var expected = "On the eighth day of Christmas my true love gave to me, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(8));
}

[Fact(Skip = "Remove to run test")]
{
var expected = "On the ninth day of Christmas my true love gave to me, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(9));
}

[Fact(Skip = "Remove to run test")]
public void Tenth_day_ten_lords_a_leaping()
{
var expected = "On the tenth day of Christmas my true love gave to me, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(10));
}

[Fact(Skip = "Remove to run test")]
public void Eleventh_day_eleven_pipers_piping()
{
var expected = "On the eleventh day of Christmas my true love gave to me, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(11));
}

[Fact(Skip = "Remove to run test")]
public void Twelfth_day_twelve_drummers_drumming()
{
var expected = "On the twelfth day of Christmas my true love gave to me, twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(12));
}

[Fact(Skip = "Remove to run test")]
public void Recites_first_three_verses_of_the_song()
{
var expected =
"On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.\n" +
"On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(1, 3));
}

[Fact(Skip = "Remove to run test")]
public void Recites_three_verses_from_the_middle_of_the_song()
{
var expected =
"On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(4, 6));
}

[Fact(Skip = "Remove to run test")]
public void Recites_the_whole_song()
{
var expected =
"On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.\n" +
"On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the seventh day of Christmas my true love gave to me, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the eighth day of Christmas my true love gave to me, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the ninth day of Christmas my true love gave to me, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the tenth day of Christmas my true love gave to me, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the eleventh day of Christmas my true love gave to me, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n" +
"On the twelfth day of Christmas my true love gave to me, twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
Assert.Equal(expected, TwelveDays.Recite(1, 12));
}
}
using System.Collections.Generic;
using System.Linq;
using NUnit.Framework;
using NUnit.Framework.Constraints;

[TestFixture]
public class TwelveDaysTest
{
private TwelveDaysSong twelveDaysSong;

[SetUp]
public void Setup()
{
twelveDaysSong = new TwelveDaysSong();
}

[Test]
public void Return_verse_1()
{
var expected = "On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(1), Is.EqualTo(expected));
}

[Test]
public void Return_verse_2()
{
var expected = "On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(2), Is.EqualTo(expected));
}

[Test]
public void Return_verse_3()
{
var expected = "On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(3), Is.EqualTo(expected));
}

[Test]
public void Return_verse_4()
{
var expected = "On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(4), Is.EqualTo(expected));
}

[Test]
public void Return_verse_5()
{
var expected = "On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(5), Is.EqualTo(expected));
}

[Test]
public void Return_verse_6()
{
var expected = "On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(6), Is.EqualTo(expected));
}

[Test]
public void Return_verse_7()
{
var expected = "On the seventh day of Christmas my true love gave to me, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(7), Is.EqualTo(expected));
}

[Test]
public void Return_verse_8()
{
var expected = "On the eighth day of Christmas my true love gave to me, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(8), Is.EqualTo(expected));
}

[Test]
public void Return_verse_9()
{
var expected = "On the ninth day of Christmas my true love gave to me, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(9), Is.EqualTo(expected));
}

[Test]
public void Return_verse_10()
{
var expected = "On the tenth day of Christmas my true love gave to me, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(10), Is.EqualTo(expected));
}

[Test]
public void Return_verse_11()
{
var expected = "On the eleventh day of Christmas my true love gave to me, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(11), Is.EqualTo(expected));
}

[Test]
public void Return_verse_12()
{
var expected = "On the twelfth day of Christmas my true love gave to me, twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n";

Assert.That(twelveDaysSong.Verse(12), Is.EqualTo(expected));
}

[Test]
public void Return_multiple_verses()
{
var expected = "On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.\n\n" +
"On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.\n\n" +
"On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n\n";

Assert.That(twelveDaysSong.Verses(1, 3), Is.EqualTo(expected));
}

[Test]
public void Return_entire_song()
{
Assert.That(twelveDaysSong.Verses(1, 12), Is.EqualTo(twelveDaysSong.Sing()));
}
}

internal class TwelveDaysSong
{
private Dictionary<int, string> numbers = new Dictionary<int, string>
{
{ 1, "first"},
{ 2, "second"},
{ 3, "third"},
{ 4, "fourth"},
{ 5, "fifth"},
{ 6, "sixth"},
{ 7, "seventh"},
{ 8, "eighth"},
{ 9, "ninth"},
{ 10, "tenth"},
{ 11, "eleventh"},
{ 12, "twelfth"},
};
private string song =
" twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.";
public string Verse(int i)
{
var start = \$"On the {numbers[i]} day of Christmas my true love gave to me,";
if (i == 1)
return start + " a Partridge in a Pear Tree.\n";
var verse = start + string.Join(",", song.Split(',').Where((x, y) => y >= 12 - i)) + "\n";
return verse;
}

public string Verses(int i, int i1)
{
string verses = "";
for (int j = i; j <= i1; j++)
{
verses += Verse(j) + "\n";
}
return verses;
}

public string Sing()
{
return Verses(1, 12);
}
}