From 6e5c7cbb5923f7627abc3b720600b6f1df718132 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Sun, 28 Aug 2016 02:36:40 +0200 Subject: Solve roman --- go/roman-numerals/README.md | 61 ++++++++++++++++++++++++++++++++ go/roman-numerals/cases_test.go | 31 ++++++++++++++++ go/roman-numerals/roman_numerals.go | 19 ++++++++++ go/roman-numerals/roman_numerals_test.go | 39 ++++++++++++++++++++ 4 files changed, 150 insertions(+) create mode 100644 go/roman-numerals/README.md create mode 100644 go/roman-numerals/cases_test.go create mode 100644 go/roman-numerals/roman_numerals.go create mode 100644 go/roman-numerals/roman_numerals_test.go diff --git a/go/roman-numerals/README.md b/go/roman-numerals/README.md new file mode 100644 index 0000000..fdcbc5a --- /dev/null +++ b/go/roman-numerals/README.md @@ -0,0 +1,61 @@ +# Roman Numerals + +Write a function to convert from normal numbers to Roman Numerals: e.g. + +The Romans were a clever bunch. They conquered most of Europe and ruled +it for hundreds of years. They invented concrete and straight roads and +even bikinis. One thing they never discovered though was the number +zero. This made writing and dating extensive histories of their exploits +slightly more challenging, but the system of numbers they came up with +is still in use today. For example the BBC uses Roman numerals to date +their programmes. + +The Romans wrote numbers using letters - I, V, X, L, C, D, M. (notice +these letters have lots of straight lines and are hence easy to hack +into stone tablets). + +``` + 1 => I +10 => X + 7 => VII +``` + +There is no need to be able to convert numbers larger than about 3000. +(The Romans themselves didn't tend to go any higher) + +Wikipedia says: Modern Roman numerals ... are written by expressing each +digit separately starting with the left most digit and skipping any +digit with a value of zero. + +To see this in practice, consider the example of 1990. + +In Roman numerals 1990 is MCMXC: + +1000=M +900=CM +90=XC + +2008 is written as MMVIII: + +2000=MM +8=VIII + +See also: http://www.novaroma.org/via_romana/numbers.html + +To run the tests simply run the command `go test` in the exercise directory. + +If the test suite contains benchmarks, you can run these with the `-bench` +flag: + + go test -bench . + +For more detailed info about the Go track see the [help +page](http://exercism.io/languages/go). + +## Source + +The Roman Numeral Kata [http://codingdojo.org/cgi-bin/wiki.pl?KataRomanNumerals](http://codingdojo.org/cgi-bin/wiki.pl?KataRomanNumerals) + +## Submitting Incomplete Problems +It's possible to submit an incomplete solution so you can see how others have completed the exercise. + diff --git a/go/roman-numerals/cases_test.go b/go/roman-numerals/cases_test.go new file mode 100644 index 0000000..8e99b8e --- /dev/null +++ b/go/roman-numerals/cases_test.go @@ -0,0 +1,31 @@ +package romannumerals + +// Source: exercism/x-common +// Commit: 6985644 Merge pull request #121 from mikeyjcat/add-roman-numerals-test-definition + +type romanNumeralTest struct { + arabic int + roman string + hasError bool +} + +var romanNumeralTests = []romanNumeralTest{ + {1, "I", false}, + {2, "II", false}, + {3, "III", false}, + {4, "IV", false}, + {5, "V", false}, + {6, "VI", false}, + {9, "IX", false}, + {27, "XXVII", false}, + {48, "XLVIII", false}, + {59, "LIX", false}, + {93, "XCIII", false}, + {141, "CXLI", false}, + {163, "CLXIII", false}, + {402, "CDII", false}, + {575, "DLXXV", false}, + {911, "CMXI", false}, + {1024, "MXXIV", false}, + {3000, "MMM", false}, +} diff --git a/go/roman-numerals/roman_numerals.go b/go/roman-numerals/roman_numerals.go new file mode 100644 index 0000000..21727e2 --- /dev/null +++ b/go/roman-numerals/roman_numerals.go @@ -0,0 +1,19 @@ +package romannumerals + +import "errors" + +const testVersion = 2 + +var ( + m0 = []string{"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"} + m1 = []string{"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"} + m2 = []string{"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"} + m3 = []string{"", "M", "MM", "MMM"} +) + +func ToRomanNumeral(n int) (string, error) { + if n < 1 || n >= 4000 { + return "", errors.New("out of range") + } + return m3[n%1e4/1e3] + m2[n%1e3/1e2] + m1[n%1e2/1e1] + m0[n%1e1], nil +} diff --git a/go/roman-numerals/roman_numerals_test.go b/go/roman-numerals/roman_numerals_test.go new file mode 100644 index 0000000..637e52e --- /dev/null +++ b/go/roman-numerals/roman_numerals_test.go @@ -0,0 +1,39 @@ +package romannumerals + +import "testing" + +const targetTestVersion = 2 + +func TestRomanNumerals(t *testing.T) { + if testVersion != targetTestVersion { + t.Fatalf("Found testVersion = %v, want %v", testVersion, targetTestVersion) + } + tc := append(romanNumeralTests, []romanNumeralTest{ + {0, "", true}, + {-1, "", true}, + {4000, "", true}, + {3999, "MMMCMXCIX", false}, + }...) + for _, test := range tc { + actual, err := ToRomanNumeral(test.arabic) + if err == nil && test.hasError { + t.Errorf("ToRomanNumeral(%d) should return an error.", test.arabic) + continue + } + if err != nil && !test.hasError { + t.Errorf("ToRomanNumeral(%d) should not return an error.", test.arabic) + continue + } + if actual != test.roman { + t.Errorf("ToRomanNumeral(%d): %s, expected %s", test.arabic, actual, test.roman) + } + } +} + +func BenchmarkRomanNumerals(b *testing.B) { + for i := 0; i < b.N; i++ { + for _, test := range romanNumeralTests { + ToRomanNumeral(test.arabic) + } + } +} -- cgit v1.2.3