Initial Commit

go/anagram/README.md

@@ -0,0 +1,21 @@
+# Anagram
+
+Write a program that, given a word and a list of possible anagrams, selects the correct sublist.
+
+Given `"listen"` and a list of candidates like `"enlists" "google"
+"inlets" "banana"` the program should return a list containing
+`"inlets"`.
+
+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
+
+Inspired by the Extreme Startup game [view source](https://github.com/rchatley/extreme_startup)

go/anagram/anagram.go

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+package anagram
+
+import "strings"
+
+// Detect returns all candidates that are anagrams of subject
+func Detect(subject string, candidates []string) []string {
+	var ret []string
+	for i := range candidates {
+		if isAnagram(subject, candidates[i]) {
+			ret = append(ret, strings.ToLower(candidates[i]))
+		}
+	}
+	return ret
+}
+
+func isAnagram(s, c string) bool {
+	s = strings.ToLower(s)
+	c = strings.ToLower(c)
+	if s == c || len(s) != len(c) {
+		return false
+	}
+	for _, v := range strings.Split(s, "") {
+		if strings.Count(s, v) != strings.Count(c, v) {
+			return false
+		}
+	}
+	return true
+}

go/anagram/anagram_test.go

@@ -0,0 +1,172 @@
+package anagram
+
+import (
+	"fmt"
+	"sort"
+	"testing"
+)
+
+var testCases = []struct {
+	subject     string
+	candidates  []string
+	expected    []string
+	description string
+}{
+	{
+		subject: "diaper",
+		candidates: []string{
+			"hello",
+			"world",
+			"zombies",
+			"pants",
+		},
+		expected:    []string{},
+		description: "no matches",
+	},
+	{
+		subject: "ant",
+		candidates: []string{
+			"tan",
+			"stand",
+			"at",
+		},
+		expected:    []string{"tan"},
+		description: "simple anagram",
+	},
+	{
+		subject: "listen",
+		candidates: []string{
+			"enlists",
+			"google",
+			"inlets",
+			"banana",
+		},
+		expected:    []string{"inlets"},
+		description: "another simple anagram",
+	},
+	{
+		subject: "master",
+		candidates: []string{
+			"stream",
+			"pigeon",
+			"maters",
+		},
+		expected:    []string{"maters", "stream"},
+		description: "multiple anagrams",
+	},
+	{
+		subject: "allergy",
+		candidates: []string{
+			"gallery",
+			"ballerina",
+			"regally",
+			"clergy",
+			"largely",
+			"leading",
+		},
+		expected:    []string{"gallery", "largely", "regally"},
+		description: "multiple anagrams (again)",
+	},
+	{
+		subject: "galea",
+		candidates: []string{
+			"eagle",
+		},
+		expected:    []string{},
+		description: "does not confuse different duplicates",
+	},
+	{
+		subject: "corn",
+		candidates: []string{
+			"corn",
+			"dark",
+			"Corn",
+			"rank",
+			"CORN",
+			"cron",
+			"park",
+		},
+		expected:    []string{"cron"},
+		description: "identical word is not anagram",
+	},
+	{
+		subject: "mass",
+		candidates: []string{
+			"last",
+		},
+		expected:    []string{},
+		description: "eliminate anagrams with same checksum",
+	},
+	{
+		subject: "good",
+		candidates: []string{
+			"dog",
+			"goody",
+		},
+		expected:    []string{},
+		description: "eliminate anagram subsets",
+	},
+	{
+		subject: "Orchestra",
+		candidates: []string{
+			"cashregiser",
+			"carthorse",
+			"radishes",
+		},
+		expected:    []string{"carthorse"},
+		description: "subjects are case insensitive",
+	},
+	{
+		subject: "orchestra",
+		candidates: []string{
+			"cashregiser",
+			"Carthorse",
+			"radishes",
+		},
+		expected:    []string{"carthorse"},
+		description: "candidates are case insensitive",
+	},
+}
+
+func equal(a []string, b []string) bool {
+	if len(b) != len(a) {
+		return false
+	}
+
+	sort.Strings(a)
+	sort.Strings(b)
+	return fmt.Sprintf("%v", a) == fmt.Sprintf("%v", b)
+}
+
+func TestDetectAnagrams(t *testing.T) {
+	for _, tt := range testCases {
+		actual := Detect(tt.subject, tt.candidates)
+		if !equal(tt.expected, actual) {
+			msg := `FAIL: %s
+	Subject %s
+	Candidates %v
+	Expected %v
+	Got %v
+				`
+			t.Fatalf(msg, tt.description, tt.subject, tt.candidates, tt.expected, actual)
+		} else {
+			t.Logf("PASS: %s", tt.description)
+		}
+	}
+}
+
+func BenchmarkDetectAnagrams(b *testing.B) {
+
+	b.StopTimer()
+
+	for _, tt := range testCases {
+		b.StartTimer()
+
+		for i := 0; i < b.N; i++ {
+			Detect(tt.subject, tt.candidates)
+		}
+
+		b.StopTimer()
+	}
+
+}