unique-chars/Makefile

@@ -0,0 +1,48 @@
+.DEFAULT_GOAL := help
+
+# ==================================================================================== #
+# HELPERS
+# ==================================================================================== #
+
+## help: print this help message
+.PHONY: help
+help:
+	@echo 'Usage:'
+	@sed -n 's/^##//p' ${MAKEFILE_LIST} | column -t -s ':' |  sed -e 's/^/ /'
+
+
+# ==================================================================================== #
+# QUALITY CONTROL
+# ==================================================================================== #
+
+## tidy: format code and tidy modfile
+.PHONY: tidy
+tidy:
+	go fmt ./...
+	go mod tidy -v
+
+## audit: run quality control checks
+.PHONY: audit
+audit:
+	go mod verify
+	go vet ./...
+	go run honnef.co/go/tools/cmd/staticcheck@latest -checks=all,-ST1000,-U1000 ./...
+	go run golang.org/x/vuln/cmd/govulncheck@latest ./...
+	go test -race -buildvcs -vet=off ./...
+	go run github.com/golangci/golangci-lint/cmd/golangci-lint@latest run -v ./...
+
+
+# ==================================================================================== #
+# DEVELOPMENT
+# ==================================================================================== #
+
+## test: run all tests
+.PHONY: test
+test:
+	go test -v -race -buildvcs ./...
+
+## test/cover: run all tests and display coverage
+.PHONY: test/cover
+test/cover:
+	go test -v -race -buildvcs -coverprofile=/tmp/coverage.out ./...
+	go tool cover -html=/tmp/coverage.out

unique-chars/go.mod

@@ -0,0 +1,10 @@
+module uniqueschars
+
+go 1.21.6
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.4 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

unique-chars/go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

unique-chars/main.go

@@ -0,0 +1,19 @@
+package uniqueschars
+
+import "unicode"
+
+func Unique(s string) bool {
+	m := make(map[rune]struct{}, 50)
+
+	for _, c := range s {
+		c := unicode.ToLower(c)
+
+		if _, ok := m[c]; ok {
+			return false
+		}
+
+		m[c] = struct{}{}
+	}
+
+	return true
+}

unique-chars/main_test.go

@@ -0,0 +1,43 @@
+package uniqueschars
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestUnique(t *testing.T) {
+	cases := []struct {
+		Name     string
+		input    string
+		expected bool
+	}{
+		{
+			"eng alphabet",
+			"abcdefghijklmnopqrstuvwxyz",
+			true,
+		},
+		{
+			"eng mixed case",
+			"aAbBfF",
+			false,
+		},
+		{
+			"cyrillic alphabet",
+			"абвгдеёжзийклмнопрстуфхцчшщъыьэюя",
+			true,
+		},
+		{
+			"cyrillic case mixed",
+			"аАбБвВ",
+			false,
+		},
+	}
+
+	for _, tc := range cases {
+		tc := tc
+
+		t.Run(tc.Name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, Unique(tc.input))
+		})
+	}
+}