HW2 is completed

hw02_unpack_string/go.mod

@@ -1,10 +1,9 @@
-module github.com/fixme_my_friend/hw02_unpack_string
+module github.com/sofiiakulish/hw/tree/hw02_unpack_string
 
 go 1.16
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/stretchr/testify v1.7.0
-	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )

hw02_unpack_string/go.sum

@@ -1,20 +1,13 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 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/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.5.0 h1:DMOzIV76tmoDNE9pX6RSN0aDtCYeCg5VueieJaAo1uw=
-github.com/stretchr/testify v1.5.0/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
-gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

hw02_unpack_string/unpack.go

@@ -2,11 +2,38 @@ package hw02unpackstring
 
 import (
 	"errors"
+	"strconv"
+	"strings"
+	"unicode"
 )
 
 var ErrInvalidString = errors.New("invalid string")
 
-func Unpack(_ string) (string, error) {
-	// Place your code here.
-	return "", nil
+func Unpack(s string) (string, error) {
+	var b strings.Builder
+	var last rune
+	for _, r := range s {
+		if unicode.IsDigit(r) {
+			if last == 0 {
+				return "", ErrInvalidString
+			}
+
+			counter, _ := strconv.Atoi(string(r))
+			if counter > 1 {
+				b.WriteString(strings.Repeat(string(last), counter-1))
+			} else if counter == 0 {
+				current := b.String()
+				current = current[:len(current)-len(string(last))]
+				b.Reset()
+				b.WriteString(current)
+			}
+
+			last = 0
+		} else {
+			b.WriteRune(r)
+			last = r
+		}
+	}
+
+	return b.String(), nil
 }

hw02_unpack_string/unpack_test.go

@@ -16,6 +16,8 @@ func TestUnpack(t *testing.T) {
 		{input: "abccd", expected: "abccd"},
 		{input: "", expected: ""},
 		{input: "aaa0b", expected: "aab"},
+		{input: "qweЯ0", expected: "qwe"},
+		{input: "А2Б3", expected: "ААБББ"},
 		// uncomment if task with asterisk completed
 		// {input: `qwe\4\5`, expected: `qwe45`},
 		// {input: `qwe\45`, expected: `qwe44444`},