Merge pull request #3 from yitsushi/day10

Day 10

cmd/aoc2021/register.go

@@ -12,6 +12,7 @@ import (
 	"github.com/yitsushi/advent-of-code-2021/days/day07"
 	"github.com/yitsushi/advent-of-code-2021/days/day08"
 	"github.com/yitsushi/advent-of-code-2021/days/day09"
+	"github.com/yitsushi/advent-of-code-2021/days/day10"
 )
 
 func withDays(month puzzle.Month) puzzle.Month {
@@ -24,6 +25,7 @@ func withDays(month puzzle.Month) puzzle.Month {
 	month.Register(7, &day07.Solver{})
 	month.Register(8, &day08.Solver{})
 	month.Register(9, &day09.Solver{})
+	month.Register(10, &day10.Solver{})
 
 	return month
 }

days/day10/error.go

@@ -0,0 +1,13 @@
+package day10
+
+import "fmt"
+
+// UnknownCharacterError occurs when an unknown character was found ina
+// sequence.
+type UnknownCharacterError struct {
+	Character rune
+}
+
+func (e UnknownCharacterError) Error() string {
+	return fmt.Sprintf("unknown character: %c", e.Character)
+}

days/day10/fixtures/example

@@ -0,0 +1,10 @@
+[({(<(())[]>[[{[]{<()<>>
+[(()[<>])]({[<{<<[]>>(
+{([(<{}[<>[]}>{[]{[(<()>
+(((({<>}<{<{<>}{[]{[]{}
+[[<[([]))<([[{}[[()]]]
+[{[{({}]{}}([{[{{{}}([]
+{<[[]]>}<{[{[{[]{()[[[]
+[<(<(<(<{}))><([]([]()
+<{([([[(<>()){}]>(<<{{
+<{([{{}}[<[[[<>{}]]]>[]]

days/day10/fixtures/example-ignore-extra

@@ -0,0 +1,3 @@
+[({(<(())[]a>[[{[]{<()<>>
+{([(<{}[<>[]}>{[]{[(<()>
+{([(<{}[<>[4]}>{[]{[(<()>

days/day10/fixtures/input

@@ -0,0 +1,110 @@
+[<(<<([[[{<[{[[]()](<>())}<{()[]}<[]<>>>](<[()[]][()()]>)>[{{(()())(<>())}({()[]}{{}{}})}[(
+{{{(({[<<[{[(<()()>[<>{}])<<()()>[[]]>]{{<(){}>{()[]}}([()<>]<<>{}>)}}([[<[][]>({}{})]<({}[])
+<[[[(<[{{{(<({()<>)([][]))(<{}()>{[][]})>{[[{}()][[][]]]({{}[]}[()()])})}[{<([()()]{()<>}){([]
+[{[(<<{({{<<<{<>[]}{{}}>[({}<>){<>}]>[<<{}()>{<>[]}>[(()())({}())]]>}}({[(<({}{})<<>{}>>{<()()><[
+{{[{<<{[<{([({[]{}})])}>]}>><<<[[[<[([<>{}])<{[]{}}(<><>))]>]]({([{(<>())(()[])}<<()<>>>]<
+((<<{<[{[((<([()[]])<{<>{}}>>((<{}[]><(){}>)[<()<>>(<>())])}[<{<()[]>{()()}}>])]([{<{<()[]>({}<>)}>}]{
+{<[<<({{<<{(<<()()>((){})>[{<>()}{(){}}]){(<()()>){([]{})[()]}}}[([<<>[]>{{}}])]>>(<{([[[][]]({
+<({{[[[[[<[(<((){})({})>)[<({}<>)(<>)>{{<>}}]]><[<{[[][]]<<>{}>}{(<>()){[]{}}}>{({()}<()[]
+<<{<{{[[([<{{[(){}]<()[]>}<{<><>}[[][]]>}>[[[<()[]>]<{<>()}<[]{}>>]}]{<(<<<>{}>(<>[])>[{()(
+({{(({<([(<{{[[][]]<{}<>>}{{[]<>}}}>[({{()<>}(<>[])}<<<>[]>>){[([]{})]<{()<>}{(){}}>}])[<[{[{}[]]}[
+<([<{[{(<[[[((()[])[[]()]){[[]()](()<>)}][<(<>[]){()()}>{(<><>)[<>]}]]][((({{}[]}{[]()}))<[[{}<>]<[]
+{[[([<[<{({{{[<>{}]{(){}}}{{[]{}}<{}<>>}}<(<()<>>{()[]})<(<>())[[]()]>>}[<[{[]<>}(()()))<<[]{}>{<
+{<<<(([(((<[{(()[]){()<>}}]>)([<[<<><>>((){})]>][{[[{}[]][{}<>]]<<()<>>[{}[]]>}[[<<>{}>[{}[]]]<{[]()}>]]
+{{[(<<<(({{<<{{}<>}[<>[]]>([[]<>]<{}{}>)>{({{}{}}{[]<>})}}}[[{<{<><>}(<>())>{[()]}}<[(<>{})
+((({([{[[<{{([{}][{}<>]){[[]{}]{{}<>}}}[<{<>{}}><[[]{}]<<>()>>]}([(<()[]>[<>])[[[]()](())]
+({{<[{{<(([<{<<>[]><{}{}>}[(<>{})<()[]>]><[[[][]](()())](<[]()>(<>[]))>]{<{<{}[]>[{}[]>}><[[[]{}]<[]{}
+{{<[{<[<{[{((<[]<>>{{}[]})[([]<>)(()())])}][({[({}()){{}<>}]}({<[][]><<><>>}<[()<>]<[]<>>>))(<<<<>{}><(){}>
+{[<[{<{((<[(<([][])[(){}]>{([]())<[][]>})<{<<><>>{<>}}>]<<[{{}()}{<><>}][[{}()]{[]<>)]>{[{[]<>}<{}{}>]((<>
+<(<({(([{<[((<[]{}>[()[]]){((){})[(){}]})[[<[][]>{()<>}]({{}()})]]([(<<>()>{<>})<({}{})({}<>)>]((<<
+<<<[<<[(<<{{(<<>()>([]()))[{(){}}{{}[]}]}{<[(){}]>{[<>[]]([]<>)}}}([<<<><>>([]<>)]]{{<()()>{{}[]}}[{<
+{[<(<([([[<[{{<>{}}<{}()>}{<[]<>><<>()>}][{((){})[{}<>]}<{<>()}{<>{}}>]>{{<<[][]>[<>[]]><<()<>><[]<>>>}
+[{({<[{{([[[{({}<>)[<>[])}[[[][]]({}())]]](<<<(){}>[<>]>({(){}})>[(({}()){{}{}})<<<>{}>{<>[]}>])])}
+<[[<<((((<<([<()<>>{[]()}]({{}{}}<[]()>))>>{<<<{<>{}}>{(()[]){[][]}}>(({{}{}})[[<><>]{{}{}
+({[({<[{{[(([{<>()}([][])](<<>{}><[]>))[{{[]<>}<<>()>><[<>()]>])]}<<{<([()<>]){{(){}}(()())}
+((<{{<(<{<<({(<>{})}<[{}<>]{[]<>}>){{[<>]<<><>>}{[<>()]((){})}}>({({{}()}{()()}){[<>()]<<>{}>}}(<({}<>)([]())
+{{[<{({{[[({<([]<>)(()<>)>([{}<>]{()()})}([{{}{}}<<>[]>]{<()[]>{()()}}))]<<[{[<>()]<{}[]]}[[[]()
+[((<<{(<{(([{[<>{}]({}[])}([{}[]][()<>])])[[[(<>())([]<>)]]]){<([{[]{}}[<>()]]<[<>[]][<>{}]>)(<({}{})
+((<([(<<([{(<<<>{}><<><>>>[{[]()}])[{[<>{}][[]{}]}]}([[{<>()}({}[])]<<{}>{(){}}>]{[<[]<>>[(){}]>})][<<((()()
+<[<[<{({{{{({[[][]][<>[]]}<[[][]]>)[[<[]>((){})]]}<(<([]()){[][]}>[<<><>><[]<>>]]{(<<><>>)[<()[]>
+{<[((<(<[({<({[]()}([]{}])<[<>{}]{{}<>}>>({<()()><<>{}>}{[<><>]<<>[]>})}{[((<>)[[]()])]})[({{[()[]]<
+<{({[[{<{[<{([()[]][{}{}])}>({[<()()>(<><>)]<[()<>]([][])>}([<{}<>>(<>[])]({<>[]}(<>()))))]}(([{(([])
+<<(([[[({(<({[{}()]<()()>}<[{}{}]<[]()>>){[(<>{})[<>[]]][(()<>)(<>())]}>(<<[()()]([]{})>[[[]{}]{(){}}]
+({<{<<<{<<{(<<[]{}>([]{})><{{}}[()<>]>)}[([([]{})[{}[]]]{{<><>}[()<>]})]>{{<{<<>{}>}(<[]{}>[[]])>[<<()()><()
+(<<{[<{<{(<{[[{}[]]<()[]>]([()][{}[]])}(({()[]})({<><>}<{}<>>))>[[[<[][]>{(){}}]][<[(){}][{}]
+[[{{({[<<([{{[<><>]{<>{}}}}])><[{[{[[][]]{()<>>}{({}<>){[]}}]({{<>{}}<[]()>})}<{[<()<>>]([()[]][()])}{{<[]
+[([({<[[[[<<<[<>][<><>]><{[][]}{<>[]}>><{[[]]<<>{}>}>>[[(({}<>){{}<>})[<()[]>[()[]]]]]>{([{{<>}<
+{{[<[[<<{<{({{(){}}{(){}}}({<>()}{{}{}}))((({}())({}<>))([{}()][{}<>]))}>({(({()[]}){(<><>)<{}>}](<
+[({[<{{([[{([{()<>}<<>{}>]{<[]{}>})}({{[<>{})<{}()>}[[[][]]<{}[]>]})]]{<{<[<{}()>]>{{{()}(<>
+{[(([[(([<[(({()}<()<>>)<(<>[])({}[])>)]>])({[([[({}<>){<>()}](<{}<>>)](<((){})[<>[]])))([<([]())({}<>)>{[{}
+{([[({[[(<<(<[<>()]{{}()}>)<<(()[])>>><(((<>{})[[][]])[[[][]]{<>[]}])({<<>{}><{}[]>}<{{}[]}>)>>[{(([{}
+[(([<{[<<[<{<[{}{}]{[]()}><(<>())([]{})>}{[{[]()}[{}[]]]((()<>){()()})}>{([{<>[]}([]{})]<{[][]}({}{})>){{[[]{
+[<{<[<[([{{{{<<><>>}((()()){[]()})}{{{{}<>}([]{})}([<><>]{()()])}}{{({<>{}}<{}{}>)[<<><>>({}())]}}}<
+[<[[<{[((({(([<>{}]([][])){{[]()}<[][]>})[{[()<>}<()<>>}{<{}[]>}]}(<([<>{}]([]())){({}[])[<>{
+[{{<{<[<{([({([]())([]{})}{<()[]>[()<>]])(([<>{}][()[]])(<{}{}><()<>>))])}>]({(<[<(([]<>)([]<>))<[()<>](()
+<({<(([[<<[[{[{}()][()<>]}((<>[])[[]])]]{{<{{}{}}{<><>}><(<>)([]{}))}({(<>{})(<>[])}{<{}<>>{<>()}})}>({{{<
+(({<[([(<<(<(<<><>>)({{}()})>{{[<>()]}}){{[[()[]]{<>{}}]({[]{}})}[([()<>]{{}()}){{[]{}}(<>[])}]}>>({(<(((
+<[[{([<<[[(<<([][])[<>]>[[<>[]]]>)([<(()())<()[]>><[{}][[]]>])]((<[((){})[[]()]]<({}[]>[{}[]]>>
+[(<<<<({<[{<<<(){}>{[]{}}>([{}{}]({}[]))><<<[]{}>(()[])>{[{}()](()<>)}>}][<<[(<>[])<(){}>]({(){}}((){
+<[[[[{(<{([{((<>())[()<>]){<{}[]><{}()>}}][{{{<><>}[<>{}]}({{}{}}[<>{}])}[({(){}}[{}<>]){[{}[]]}]
+(<<[<(<(<[[{<[<>()]<<>>>{{()<>}<[]{}>}}[(<[][]>{{}()})({()[]}(()[]))]]({((()())[{}])<<{}()){{
+{{<([{{[(({([([][]){(){}}]){[{[]<>}(()<>)]<[{}]<<>>>}}<({{{}()}[{}()]}{<(){}>{<>[]}})<<[{}()]<<>()>]({
+((<<{<{[[(<[{([]())(<><>)}](<<{}()>(()<>)>[((){})[[]{}]})>([(<[]<>><{}<>>)][<<{}()>>[({}[])([][])]]))<{((
+[[<{{<[{({{[(<<>[]>[<><>])<{[]<>}<(){}>>]<[[{}<>]<{}()>]<<[][]><<>()>>>}<[({[]()})<(<><>)<<>{}
+<(({[[[<{<[(<([][])(<>{})>{{{}}[{}()]})]((<{(){}}(<>[])>([{}[]]{<>{}})){{({})}{[{}[]]}})>}{[[(((<><>}(()()))
+{[[{[({{[((<(({}{})){<[][]){{}()}}>){[({{}[]}([]{}))]{[<[]{}><[]{}>]}})({[{[[]{}]{()[]}}]<(<<>>)[{{}()}<{}<>
+{[[<{({([(<[[{{}[]}[()[]]][[[][]]({}{})]]<[<[]<>>[{}()]]<<<>()>[()()]>>>>{[([[()()]<<>[]>]
+<([[[[{([<{{(<[]{}>[[]]){<[]()>{()<>}}}[<<[][]>((){})>{{()<>}[[]{}]}]}>[{{{<()()><(){}>}<{()()}>}{[(()
+{(<{<([<[(({{[{}[]]({}[])}{{[]()}{<><>}}})[<<({}())[()[]]>{[[][]]<()[]>}>[<<()<>>([]())><[(){})<()()>>]]
+{[[(<([<(((([[{}{}]{[]()}]<(<>{})<[][]>>){{<{}{}><[][]>}[{()<>}[()[]]]})<(((<>{}){[]{}})[{[]()}
+{{<<<{[({{{{([(){}}[<>{}])[<(){}><{}{}>]}}[<[{<>{}}{{}{}}](<[]{}>[[][]])>]}({<{{{}{}}<{}[]>}([[]][{}<>]
+({{{(<[{{<[[(({}{})<[]<>>)([{}[]]{()[]})]((<()()>)[<[]{}>{<>[]}])])<[{(<{}>[[][]])<([]())[[]()]>}<
+(((<{{{(((([({()<>})<<[]<>>[<>]>])[((<<>[]>({}))[[[]()]<<><>>])(<{[][]}[{}()]><{{}[]}[()()]>)
+{[<[[<{<<({(<(<>()){[]()}><([]{})[<>{}]>)[[<{}[]><[]{}>][[{}[]]<[]<>>]]})>[<{<([()<>]{{}[]})<{{}[]}<{}<>>>
+((({{[(((([{<(())({}<>)>{[[]{}][[][]]}}{<<{}<>>{{}[]}>{(<><>)({}<>)}}][{{[(){}](<>{})}{<()
+{{<{({({[[<{{(()[])<()[]>}}[[{{}<>}(()[])][{{}{}}{{}<>}]]>{((<{}[]>{[]<>})({[]<>}{[][]}))[([[]<>]<()()>)<<<
+[[{{{{{[[{[(<[{}()]{[]()}><<()()>[(){}]>)<[[{}<>]{<>[]}]>]([(<{}<>>[[][]]){(<><>)(()[])]]<[[
+{({<[<{[<[[([[<><>][<><>]])[{{{}()}([]<>)}[[[]()][[][]]]]]<[<<()[]]{<>[]}><([])<<>()>>]{(<()<>><
+({<<<{<<{({<{[()[]]{(){}}}{((){}){{}[]}}><<{(){}}><{<>()}<{}{}>}>}<{[[[]]([]{})](<()<>>(()<>))}>)}<<[({[<>
+(<<<<{[{<({{{(<><>)<()[]>}{{[]()}{()()}}}<[<[]{}>(<>[])]{[[]<>]<[]<>>}>})[((([<>]{(){}})([(){}]<<>
+(([(((((<<{<[<()<>><[]()>]([()[]][<>{}])>{(((){})({}[]))(<[]{}><[]<>>)}}{(<<(){}>[{}]>{{()())<()[
+(({<([({(<{((<()()>{()[]}){<[][]>[[]<>]})[[{[]}{<><>}]<<[]><{}()>>]}(<(<[]{}><{}{}>)[(<><>){{}()}]>)>
+{<<{[{[<{{{({({})<<>()>})<{[{}{}]}[[{}()]]>}}([{(({}{}}(<><>))([<>[]](<>()))}[{[{}<>]}(<<>{}>(()<>))]])}<
+({[[{{{{[<{[([<>[]]{{}{}}><<<>[]>>]{[{()()}[()()]]}}((<[{}()][<>{}]>{([]()){()[]}})({[()<>](()[]
+[[{{(({{({<{<<{}()>>{<<>()><{}()>}}{[{<>[]}<{}>]{<[]<>>[{}[]]}}>{[[[{}<>]({}{})]<[{}{}]<(){}}>][{({}
+([[<<(<[<{{[[{(){}}<()[]>]{{()[]}}]({{[]{}}[(){}]](({}{})[[][]]))}{<[{<>[]}{{}<>}]{(<>{}){()()}}>}}<<{<(
+{[<[(({[[(([[[{}()](<><>)]{{{}()}({}[])}])[<((()[])<()()>)<{<>{}}>><[{<><>}(()[])]>])](<({
+{[{<<[(<{({<[[()<>]<[]{}>][(<>){{}<>}]>}<(<<<>[]>(()())>[(()<>)[[]<>]])<[<<>{}>[<><>]]{[<>{}]{[]}}>>)[
+[{([{<([[{[([{{}<>}[{}[]]][({}{})({}{})]){({<>[]}(()()))}](<[(()[])([]{})][<()[]>{[]{}}]><{(<>())<(
+([{({(((((({<({}<>)<<>[]>>{[<>[]][<><>]}}(<({}())<<>[]>>(([]<>)[<>{}])))[{({{}()}(()[])){<[]()><()(
+{[{[{{<{<{<{(<()<>><()[]>)}<<<()[]><{}{}>>((<>[])<{}<>>)>><<(([]())[<>{}])({<>()}<{}>)>{([[]<>
+([[(<<({{{{{[{()<>}[{}<>]]{{{}<>}<(){}>}}(([[][]][()()]))}({[{{}()}{()<>}]}<[([]<>)(<>())][(<>[]
+{[<<{<<<<{<((<{}[]>[[]{}])([()<>](<>())))<{[()()]<(){}>>{<()[]>[{}{}]}>>}<[(<{{}{}}[{}{}]>)[([[]
+<{{[(<(<{([{({{}[]})(<{}[]>{()<>})}]<[<<[]<>>([]<>)>{<[]{}><<>[]>}][[{()<>}[[]()]][{[]<>}(())]]>)([[[<{}
+(<(<{<[({[<(<<{}<>>{{}()}>{(<>[])<()>})<{(<>())<{}()>}{[()()]<[]{}>}>><(({(){}}[[]{}]){{{}
+[<[[[([{{<{[([<>]<[]()>){<()>[{}<>]}]{({[]()}[{}{}])[({}[])({}())]}}>}(<(<[[()[]]<(){}>]<<[][]>{()()}>>)((
+[<<{<<([<{<(<(<>{}){()<>}>(({}{})({}{})))<<(<>[]){[][]]>{[{}{}]{()()}}>><[[[<><>]{[]{}}](<{}<
+<{<{(<<((<{{[<<>()>[()<>]]{{<>()}(<>{}))}}>({[{{[]{}}[[][]]}({(){}}[[]()])][[<<>[]>[{}<>]]{(<>[])[(){
+((({([<{[[<(({{}{}}[{}()])(([]()){{}{}})){<<[]<>>{{}()}>{{{}[]}{[]()}}}>[((<()[]>(()()))((()<>)([]{})))((
+<(<<([{[(<<<{[{}<>]{()()}}(<<>>)>([([]()){[]<>}][[()<>][<>()]])>{[<((){})[{}[]]>{((){})({}())}][([<>[]]{[]
+{[({{[<{<[<(<([]<>)(<>())>[<(){}>({}[])])>]>([<{[{[]}{{}<>}][({}<>)[[]<>]]}[{(<>[])(<><>)}({()<>>{[][]
+<((((<<<{<[(<[{}{}]{{}}>){({<>()}{{}{}})[[{}<>]([]())]}]([<(()[])<{}()>>][(<[]{}>(<>{}))<(()()){[](
+<[<<(({([[[<<<[]()>[()<>]>([<>()][()()])>[{(<>[])[<>]}{<{}()><[]{}}}]]]]([<{[<{}{}>{[]{}}]<<<><>>[()()]>}>
+<[<{<{<({{{<<<[]<>>>((<>[])[{}()])][{<<>()><()()>}(<[][]>)]}<(<((){}){{}{}}>)>}})><{[{[{([{}{}]<[](
+({<{<{{([[{[((<>[]))]}<<<({}{})>(<[]{}>({}[]))>{[(<>())([]<>)]{{<>{}}{()<>}}}>]([<({<><>}{{}<>})[[[]<>](
+([[[([{[(<({([()[]])[{[][]}<{}<>>]}<(({}{}){()[]}){{<>[]}{(){}}}>)[<({<><>}{[]})(<(){}>(<><>))>{<[
+[{{<<{<{(<<({[()()]<()[]>})[{(<>[]){()[]}}{((){})(<>[])}]>}){<[[[[<><>]<[][]>]]<([[][]](<>[]))((<>{})
+<[((<{<(<[<[[<{}()>[[]<>]]([<>[]]<()>)]<<[<>[]]{()()}>]>([({()}((){}))]<{({}())[[]()]}(({}<>)<[]{}>)>
+[{{<(<{({(<<(<()[]><{}<>>)<<<>>>><<(<>[])[{}[]]>>>({[{[]<>}]<<<>[]><{}()>>}<({{}}<()<>>)<[<>()][<><>]>>))})
+([({({{{{<(<{{<>()}({}<>)}({{}<>}<[]<>>)>)>}[{(<{[[]<>][[]{}]}[[()<>]{<>}])){(<(<>[]){<>[]}><<()>[<
+{({[{{(([[<({[{}{}]})><{<<<>[]><{}[]>><{()<>}<()()>>}(<[<>()]{()()}><[{}[]]>)>]]<[[((({}())<[]()>)<<()[]>{
+[(<([{{([[<({{[]()}<(){}>}{({}<>)({}[])})>[(<{[][]}>({<>()}<[]<>>))]]{<{<<{}{}>[()[]]>[{[]<>}{()[]
+([<((<<({([[([()()][()[]])[<<>{}>]]])}]>>)[<<(([[[(<<>()>)[{<><>}([][])]][((<><>)<[]{}>)[[()()]<{}{}
+[[<{[[({[{{({[<>()][{}{}]}){[<()[]>][<()[]>[[]()]]}}}[[[([{}{}]{{}<>})[[{}[]]{(){}}]]]]]}{[{[<(<
+[[<({[<{{<<[[({}[])][<{}<>>({}{})]]{(<<><>>{<>[]})}><<<{{}{}}{{}()}>{{<>}<<>>}]<<[()()]<[]<>>>([<>()]{[]<
+<{{{([{[([{{({<><>}<[]<>>)}[({[]<>}){<{}())[<>[]]}]}{<[{{}{}}[{}{}]]>[[[()()][<>[]]]<{{}<>}
+({[{{([<[<<{{<<>()><{}()>}}[[<<><>>(<>{})][{[]{}}]]><{(([]))<([]{})(<>[])>}(({<>{}}{()})(<{}{}]<<>>))>>]>[{
+<(<([{{[[([[{<[]()>[[][]]}{[{}[]]<{}{}>}]<{<<>()><{}{}>}({{}})>]<((<()<>>[{}[]])({{}}<{}()>)){([[]<>]{<
+(({{(((<<{<{<{{}[]}<[]()>>[<()<>><{}<>>]}>[[(([][])<[]<>>)][[<()()><[]>]{(<><>)<()()>}]]}[<[<{()<>}
+(({{{{(<[<{([{{}()}<<>{}>][<{}[]>])}[{{{[]<>}[[]]}[<(){}>]}(<{[]()}{(){}}>{([]{}){[][]}})]>]>)}[([{[[[<<()<>
+(<{<[([{[(((({()}<[]()>)>))<{<[(<>[]){<>()}][(<>())(<><>)]><[<()()>][((){})<<>()>]>}{{[({}{}

days/day10/input.go

@@ -0,0 +1,22 @@
+package day10
+
+import (
+	"bufio"
+	"io"
+)
+
+// Solver is the main solver.
+type Solver struct {
+	input []string
+}
+
+// SetInput receives the input and parses its content.
+func (d *Solver) SetInput(input io.Reader) error {
+	scanner := bufio.NewScanner(input)
+
+	for scanner.Scan() {
+		d.input = append(d.input, scanner.Text())
+	}
+
+	return nil
+}

days/day10/input_test.go

@@ -0,0 +1,23 @@
+package day10_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/yitsushi/advent-of-code-2021/days/day10"
+	test "github.com/yitsushi/go-aoc/testing"
+)
+
+func TestSolver_SetInput(t *testing.T) {
+	example, err := test.LoadFixture("example")
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	day := day10.Solver{}
+	err = day.SetInput(ioutil.NopCloser(bytes.NewReader(example)))
+
+	assert.NoError(t, err)
+}

days/day10/main.go

@@ -0,0 +1,61 @@
+package day10
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/yitsushi/go-aoc/perf"
+)
+
+const (
+	missingScoreMultiplier = 5
+)
+
+// Part1 for this day.
+func (d *Solver) Part1() (string, error) {
+	defer perf.Duration(perf.Track("Part1"))
+
+	finalScore := 0
+
+	for _, sequence := range d.input {
+		valid, item, _ := parse(sequence)
+		if valid {
+			continue
+		}
+
+		finalScore += scoreError(item)
+	}
+
+	return fmt.Sprintf("%d", finalScore), nil
+}
+
+// Part2 for this day.
+func (d *Solver) Part2() (string, error) {
+	defer perf.Duration(perf.Track("Part2"))
+
+	scoreList := []int{}
+
+	for _, sequence := range d.input {
+		score := 0
+
+		valid, _, stack := parse(sequence)
+		if !valid {
+			continue
+		}
+
+		for !stack.IsEmpty() {
+			item, ok := stack.Pop().(Item)
+			if !ok {
+				continue
+			}
+
+			score = score*missingScoreMultiplier + scoreMissing(item)
+		}
+
+		scoreList = append(scoreList, score)
+	}
+
+	sort.Ints(scoreList)
+
+	return fmt.Sprintf("%d", scoreList[len(scoreList)/2]), nil
+}

days/day10/parser.go

@@ -0,0 +1,116 @@
+package day10
+
+import "github.com/yitsushi/go-aoc/generic"
+
+type (
+	blockKind string
+	blockType string
+)
+
+const (
+	squareBracket    blockKind = "square"      // []
+	curlyBracket     blockKind = "curly"       // {}
+	angleBracket     blockKind = "angle"       // <>
+	parentheses      blockKind = "parentheses" // ()
+	unknownBlockType blockKind = "unknown"
+
+	opening              blockType = "opening"
+	closing              blockType = "closing"
+	unknownBlockPosition blockType = "unknown"
+)
+
+// Item is one item XD.
+type Item struct {
+	Kind blockKind
+	Type blockType
+}
+
+func typeof(character rune) (Item, error) {
+	switch character {
+	case '[':
+		return Item{Kind: squareBracket, Type: opening}, nil
+	case ']':
+		return Item{Kind: squareBracket, Type: closing}, nil
+	case '{':
+		return Item{Kind: curlyBracket, Type: opening}, nil
+	case '}':
+		return Item{Kind: curlyBracket, Type: closing}, nil
+	case '<':
+		return Item{Kind: angleBracket, Type: opening}, nil
+	case '>':
+		return Item{Kind: angleBracket, Type: closing}, nil
+	case '(':
+		return Item{Kind: parentheses, Type: opening}, nil
+	case ')':
+		return Item{Kind: parentheses, Type: closing}, nil
+	default:
+		return Item{
+			Kind: unknownBlockType,
+			Type: unknownBlockPosition,
+		}, UnknownCharacterError{Character: character}
+	}
+}
+
+func parse(sequence string) (bool, Item, generic.Stack) {
+	stack := generic.NewStack()
+
+	for _, character := range sequence {
+		item, err := typeof(character)
+		if err != nil {
+			return false, item, stack
+		}
+
+		if item.Type == closing {
+			last, ok := stack.Pop().(Item)
+			if !ok {
+				continue
+			}
+
+			if last.Kind != item.Kind {
+				return false, item, stack
+			}
+
+			continue
+		}
+
+		stack.Push(item)
+	}
+
+	return true, Item{Kind: "", Type: ""}, stack
+}
+
+//nolint:gomnd // I see no reasons to put them in a constant.
+func scoreError(item Item) int {
+	switch item.Kind {
+	case parentheses:
+		return 3
+	case squareBracket:
+		return 57
+	case curlyBracket:
+		return 1197
+	case angleBracket:
+		return 25137
+	case unknownBlockType:
+		return 0
+	default:
+		return 0
+	}
+}
+
+//nolint:gomnd // I see no reasons to put them in a constant.
+func scoreMissing(item Item) int {
+	switch item.Kind {
+	case parentheses:
+		return 1
+	case squareBracket:
+		return 2
+	case curlyBracket:
+		return 3
+	case angleBracket:
+		return 4
+	case unknownBlockType:
+		return 0
+	default:
+		return 0
+	}
+}