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to Twelve Days in the C# Track

Published at May 11 2019 · 0 comments
Instructions
Test suite
Solution

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.

Running the tests

To run the tests, run the command dotnet test from within the exercise directory.

Initially, only the first test will be enabled. This is to encourage you to solve the exercise one step at a time. Once you get the first test passing, remove the Skip property from the next test and work on getting that test passing. Once none of the tests are skipped and they are all passing, you can submit your solution using exercism submit TwelveDays.cs

Further information

For more detailed information about the C# track, including how to get help if you're having trouble, please visit the exercism.io C# language page.

Source

Wikipedia http://en.wikipedia.org/wiki/The_Twelve_Days_of_Christmas_(song)

TwelveDaysTest.cs

// This file was auto-generated based on version 1.2.0 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")]
    public void Ninth_day_nine_ladies_dancing()
    {
        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;
using System.Linq;

public static class TwelveDays
{
    private static string[] day =
    {
        "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"
    };

    private static string[] giftList =
    {
        "two Turtle Doves",
        "three French Hens",
        "four Calling Birds",
        "five Gold Rings",
        "six Geese-a-Laying",
        "seven Swans-a-Swimming",
        "eight Maids-a-Milking",
        "nine Ladies Dancing",
        "ten Lords-a-Leaping",
        "eleven Pipers Piping",
        "twelve Drummers Drumming"
    };

    private static string[] firstGift =
    {
        "a Partridge in a Pear Tree.",
        ", and a Partridge in a Pear Tree."
    };

    private static string getGifts(int verseNumber)
    {
        if (verseNumber == 1) { return firstGift.First(); }
        string middleLine = giftList.Take(verseNumber - 1).Reverse().Aggregate((acc, val) => acc = string.Join(", ", acc, val));
        return middleLine + firstGift.Last();
    }

    public static string Recite(int verseNumber)
    {
        return string.Join(" ", "On the", day[verseNumber - 1], "day of Christmas my true love gave to me:", getGifts(verseNumber));
    }

    public static string Recite(int startVerse, int endVerse)
    {
        string multiVerse = string.Empty;
        for(int i=startVerse; i<=endVerse; i++)
        {
            multiVerse += Recite(i) + "\n";
        }
        return multiVerse.TrimEnd('\n');
    }
}

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