Day 10

Signed-off-by: Michael Shen <mishen@umich.edu>

Author: mjlshen

.github/workflows/action.yml

@@ -16,5 +16,5 @@ jobs:
  go-version: '1.17.3'
  stable: 'true'
 
- - name: Check test cooverage
+ - name: Check test coverage
  run: go test ./... -cover

day10/input.txt

@@ -0,0 +1,94 @@
+{[<([<[[(<[({<<><>><()[]>}<(()())(())>)<(([]())){<()()><{}<>)}>][(((()<>)[{}{}]){<[]<>>({}{})})]>)[(({([{}[]]
+{{[[(<[[[<[<<{()()}(<>{})>[<<><>>[[]]]>[{{[]<>}[[]]}<<[]{}>[<>[]]>]]([[[{}<>]]<<()[]>{()<>}>]([<<
+([<{[[{{((([(<[]<>>{[]<>})<([]){<>{}}>][([<>[]][[]{}])])[[{{()[]}<()[]>}<{(){}}>]]]<{(<[{}<
+(({(<{(([<[({([]())(<>())}{([]{})[{}{}]})]{(({{}()}{<>()}](<[]<>>(()[])))({[[]{}]<[]<>>})}>[[[{<<>[]>(()
+[([<([{({{[{[([]{})[{}[]]][[{}{})]}<([<>{}]<<>()>)>]}([<{[()<>]{()<>}}[[{}{}]<(){}>]><{{{}[]}[()<>]}[{{
+<(([<{{<(<[(<{()()}>(({}()){()[]}))<[<[]()>[[]()]]<{[]()}<<>{}>>>](<[([]())]>(([()()][()<>])({()<>}<[]<>>))
+[{({<(<[{({{{[()[]](<>[])}{([]{})<<>{}>}}}{{<<{}[]>(<>)><(<><>)([]())>}<{({}<>)(<><>)}{[{}{}
+([(<{<[<{[({[<[]{}><<><>>]<({}[])({}<>)>}([{{}<>}<[]()>]<<<><>>>)){({<<><>>[[]{}]}(<()<>>{()}))<{<[
+({{([(<{{{{{{([]{}){<>{}}}}{<<()>{{}{}}>[({}())(()<>)]}}[[[[{}{}](<><>)]{<()[]><[][]>}](([[]](()()))<[[]
+(<<[<{{{({{<{{(){}}{<>()}}<({}{}){[][]}>>[{<[]{}>{<>()}}<{[]<>}[()<>]>]}}({([({}[])(<>{})][{<>}])[{[()<>]<{}
+{[(<<((<[[<{<{<>()}[{}[]]>}{{((){})[()<>]}<{(){})[{}{}]>}>]({((<<>()>){[<>()]{{}()}}){{[()()][<><>]}
+{(((([[(<[({({{}()}[<>[]])<(<><>)([]())>}{<[[]<>]><<()<>><()<>>>})<[[<[]{}><<>{}>]]>]<<{{[
+[{(<[[(<(<[{<({}[])<{}{}>>(<[]<>>)}]<{(<[]()>[()()])}>>{({<{{}()}[<>()]>})<[[(<>())(<>{})]{{{}[]}}][({{}[]}
+{[[<([{[(<<[<<()()>[[]]>[{()()}]](<[()]<()[]>><<{}()>{()()}>)>><[[([{}<>]{{}()})<{{}[]}<()[]>>]]})[([{{{<>()}
+((({[(<<{(((<<{}()>><{<><>}>)))[[{<({}[])[{}[]]>}(<[<><>][()()]><[[][]]<{}[]>>)]]}((({<(<>())>[({}{
+{<{{[(<<{(<{[({}<>)<{}[]>]([(){}](<>[]))}<(({}()){[][]}}[<()[]><{}()>]>>)}<<{(<[{}()]{<>{}}>[[[]()](()
+{(<<({{([<[<[<{}<>>{[][]}]<[<><>][()[]]>>{(({}{})){<()><()()>}}]>(<({{()()}({}<>)}<([]<>){[]{}}>){([[]<>
+<(<({{{([({{<<{}<>><()[]>>[{()<>}[<>{}]]}})({([{()[]}{(){}}]<(()<>)<{}<>>>)}<{{<{}<>>[[][]]}}<[{<>}[<>
+{({{(<<([({{[(()<>)[[]<>]][(<>{})({}())]}})]{(<[<(<>()){<><>}><<{}()>[[]]>][{{<>()}{[]()}}{[()<>]{<>()}}]>)
+([<({{{([[<<[[()[]][<><>]]<<<>[]><()()>>>(<{()<>}<()[]>><{<>()}<[]{}>>)>({(<()[]]<()()>)<[<>()][{}]>
+{[{<((<[<<({<{[]{}}[()()>>({[][]}[[]()])})(([{()}{{}()}]<<{}()>{{}{}}>)<([<>()])(<{}<>><{}[]>)>)>{[{
+{{([([{(<[[{[{()<>}({}())][[[]<>]<{}{}>]}]<<[({}[])(()<>)]({(){}}[()()])>{{(())<(){}>}}>]{[<{[[]()]{<>[]}}
+<(<({<{<<<([<([]<>)([]<>)>]<{{{}{}}<<>()>}>)<<{[[]()](<>{})}(([]())<[]()>)><[{<>{}}[(){}]]>>>>>(<{<[[[{
+(([({<{(<{[<({<><>}){{[][]}}>{<([]()){{}{}}>[([][])<{}{}>]}]}[((<{()<>}>)[{{()<>}{[][]}}])]
+(<<<(({{{([[<{(){}}>{(()())(()[])}]{({{}[]}<[][]>]<{{}<>}{()}>}])<(({[[][]]{{}{}}}(([][])<(){}>)
+{<{{[[({<<{{({{}()}({}{})><[()<>][<>{}]>}([<()[]>({}())][{()<>}[()]])}{<[{(){}}<[]{}>][[[]<>][[][]]]>([[<>]
+{{{[(<([[[[{[[(){}}<{}>]<{<>[]}{{}{}}>}]<[[(<>())((){})]((<>()))]{(<[]{}>([][])){<[]<>>(()[])}}>]
+(<{[([[<(<[<{[<>{}]}(<[]<>>{{}<>})>[{(())}]]>){<{(<(<>())<{}()>>]}({<<[]<>>[[]<>]>((()<>)[<><>])}
+[<{[[(({([((({[]{}}[()()])))]>[((<<[<><>][[]()]>{[()<>][()()]}>({{<>[]}({}<>)})))]})){((<[<[<[<>()]>
+<({[{{{<{[<[({[]{}}<[]>)(({}[])({}<>))]><{((()()))[[()<>]{<>[]}]}(<((){})<{}{}>><({}[])>)]][([<{
+<(<<<<<[(<<[{{[][]}{{}{}}}{{[][]}<()>}](<([]{})[()[]]>[[{}{}]{<>()}])>([{[[]()]<<>[]>}[<<>{}>{<>
+<(<[[<[[[<<(<(()[])<{}()>><(<>{})>)[([{}{}]([]{}))]><<<[<>[]]{<>[]}>{(()<>)({}[])}>>><[[[{<
+([[{[({<({(([<(){}><[]<>>]<{()<>}({})>))([([{}<>][{}[]]){[<>[]]({}<>)}][[({}[]){[]()}]])})>[({{(<(()[]){<>
+<[<{<[{(<<[[{{(){}}({}<>)}<(()[])>]<<<()()>(()<>)>({{}})>]({[(<>{})<{}()>]{<{}<>><<><>>}}<<{()<>}
+{[{({[[(({{{{<()()>{[]{}}}{[<>[]]<()<>>}}(<<<>()><{}<>>>({()<>}[()<>])}}{<{[()[]]{(){}}}>[<<[]{}>>[((){})<(
+{{(<[<(<(<{{(<[]()><()<>>)}{((<><>))[<<>{}>{()[]}]}}>{{<({{}{}}[()<>])[<(){}>(<>[])]><<(<>{}}[{}
+[{{{[[[[{(<{<[<>[]](()[])]{{<>{}}}}{[(()()){[][]}]{([][])}}><<{<<>()>([])}[[[]{}]<{}{}>]>(([{}<>]<[]()>)
+{[[(<([[[[((({<>{}}(<>())){<{}[]>})[([<>[]](<>[])}[({}[])([]())]])([<{{}()}(<>())><[[][]][<>()]>][([()()]<<>[
+<[{[{({(<(((<<<>{}><[]()>][{{}()}{[][]}])[(((){})([][]))[[()<>][[]{}]]])[[(((){})[()])[[(){}]<{}
+[{[[<[<{{(({([(){}]<()()>](([]<>)[()[]])}<<{[][]}([][])>>)<[[([]())<{}[]>]]>){[[[{{}()}[<>[]]]{<[]{}>
+[[<([([[<<<{{[{}[]][<><>]}}{{{{}{}}}}>>>[([[(<<>[]>({}<>))<([]())<<><>>>]{{<<>[]>{<>()}}}][<{{[
+({[<<<((<<<<<<[]{}>[()()]>{[()[]]{()<>}}>[((<>()){()()}){<[][]]<{}{}>}]>{{[[{}{}]<{}[]>]([[]<>])}((
+({<<[[{{<{[[{<()><<>>}<<()[]>([][])>]]([[({}<>)[()[]]](([]{})<<>[]])]<[([]<>){[]}]>)}(((<<{}[
+<(<(<(([([[[{{[]()}{<>()}}{<{}[]>[{}()]}]{{[{}{}]<()[]>}({<>()}<(){}>)}][[{<{}()><[][]>}](<[
+[[<{<[<[<({<<{[]}<()<>>>({<><>}{[]<>})><([<>()]([][]))>}[({[{}{}]<{}[]>})({[<><>]})])>]([[{<({
+<([{[[<<[({<<[{}()]({}[])>{<[][]>{()()}}>{<(<>[])([]{})>([{}[]}[<>])}}{{[<<>[]>{[]<>}][([][]){{}{}}]
+[([({((<[{{{[<{}><<>()>]<<()[]>>}<[{{}{}}([][])]{{()<>}<(){}>}>}<{<[[][]]>({{}<>}{()[]})}>
+[[[{([({{{<{[[[][]]{()()}]}{{<<>[]>[{}[]]}[[[]()]<<>>]}>({{(<>[])[{}[]]}({<>()}[{}[]])}{{(()<
+{<{{{<[{[<{(<{[]{}}{[][]}>{{[]<>}}}}[{((()[])<()()>)[<<>[]><{}()>]}<[{<>{}}[()<>]]<[<>[]][<>{}]>>]>[<[
+<[<{[[<{<[([{({}[])(()<>)}[[<>()]{()[]}]])][[<{[<>[]][<>[]]}<{<>{}}{<>{}}>>{<<()()><()<>>>{([]()
+<[{{({<[<([[[([]{})({}())]]<[{{}}[()<>]]<{<>{}}{()}>>])<[<[<<>()>]{<{}{}>[[]<>]}><({[]()}<<><>>)[(()<>)(<>())
+{<[[[<(<[<{<({<>{}}[<><>])([{}<>]<[][]>)><<[(){}](<>[])>[({}[])<<>[]}]>}{{{(<>())(<>{})}}<((<>())
+<{(<<[{[{<{<<((){})[[]{}]><([]<>)<{}[]>>>{[[[][]]<()()>]}}{({{<>()}<<>()>}{<{}<>><()[]>})}>}<[<([<()()>{()()
+{{([<{[[((<<{<<>()><<>[]>}<(()<>)>>><<[<[][]><{}<>>]>{<([]()){[]<>}>}>))]<{(((<[[]<>]([]<>)>[{{}()}<<
+([{{({{<[[(((<[][]>{<>{}}){<()[]>{[]()}})(<({}<>)([]<>)>(([])[()<>])))(([([][]){()<>}]{{[]<>}{[](
+[{{<{({[<{<{((<>())({}[]))<{<>()}({}[])>}(<[{}()]<{}<>>>({[][]}{()<>}))}{([({}[]){{}[]}]<([][])>)}}{<{({{}(
+[{(([[[([<<(<([]()){<>}>(({}<>)(()())))[((<>{})){[()<>]<<>{}>}]>>][<{{[<()<>>{{}[]}]<<{}[]><{}[]>]}[
+{<<<(<[<[{<[<({}[])>(([])<[]<>>)]<<<{}{}>({}())>{[<>{}}<[][]>}>>[{[<<>()><()()>]{[<>[]]<[]>}}[<<<>[]>{[]()
+([(((<<(<[[<[<{}<>>(<><>)]>([<{}[]>{<>{}}]({<>{}}[()()]))]](<({<<>[]>({}[])}<[[]<>]{<>[]}>)(<{
+([{({{{[(((<<{[]()}<{}<>>>((<><>){[]()>)>({<{}()><(){}>}<[<>()]>))){((([[][]]{<>{}})[([]<>){<>[]}]
+<(({{{[(([<[{<(){}>([]<>)}(<[]><()<>>)]><<([()[]]([]()))>{[(()<>}<{}>]}>]){{[{(({}{})<(){}>){[[]]{[]
+[<{(<({<{((<<<[]<>>([]())>(((){})[[]()])>{[[<>]<{}<>>]}){[<[<>[]]({}())]{{()[]}<()>}]})<([[([]())<<
+[[<<[<{{[{({<[()<>]{<>[]}>{([][]){<><>}}}<[[{}()]][<<><>>{{}[]}]>)}{<{{({}<>)(()())}[{{}{}}[{}()]]
+({<({[{[{(([<<()()>{<>[]}>[([]<>)<()<>>]]{<{<>()}[{}{}]>((<>{}){<>{}})})([<([][])[[]{}]>(<[]()>{<>
+{[[((<{[[<<({<[]<>>[()<>]}{[()]{<>}})>[<{<<>()><()[]>}{{()[]}<()<>>}>(([{}[]]))]>[[{({<><>})}
+{{(<[{{[{<[({(()){{}<>}}(<{}[]>[[]()]))]>}({(<((()[])((){}))<{<><>}[<>()]>>)}(<<[(())<{}<>>]{[[]]<{}
+<{{([<<<<[([<[<><>][[]]><<(){}>[()()]>]<{(<><>)<<><>>}([{}{}])>)][[([<()()><<>()>])(({[]<>}([]{}]){<[]><[]
+{(<<[[<{{((([<[]<>>[{}<>]][([][]){{}{}}>)(<<<><>><[]{}>>{{(){}}[<>{}]}))({<(())[<>()]><{<>{}}(<>[])>}(({
+[[[([({([<<[[[<>{}]{<>{}}]<[<><>]{{}<>}>]>[({[()()]<<>()>}{[()()][{}()]}){({{}()}[(){}))}]>[(<{[()<>
+[{{(<<<[{(((<<()<>>([])>({<>{}}<()[]>)))[{(([]){()<>})(({}[])<{}})}<{([]{})({}())}<(<>[])<<>[]>>>
+{<<<<[{[{({{[<<>()><{}[]>]<[[]{}][{}{}]>}(<({}{})<()<>>>{{()<>}})}{[[{{}{}}[{}{}]]<[<><>](<>{})>]})(([{[<>()
+<(<[<{(<{[{<{[[]{}]{{}[]}}>[{[[]<>][{}{}]}(([]())(<>))]}<{{[{}{}]([]{})}[({}())]}{<<<>()>>([(
+<{{[{[<{[[<[{<[]{}><<>{}>}]{({()<>}(<><>)){[<>[]]}}>{([[<>{}]({}{})](({}{})<[]{}>))<{[{}<>
+{{<<{<<<[{[[([[]()][()()])(({}()))][[({}[])<()()>]]]{<[<{}[]>{{}{}}]>}}[[[[([]())]([<>[]][[]{}]>]]
+[[<<[({{{(<[(<()<>>[<>])]([(()<>){<>())]([<>[]][[]<>]))>{{[[[]()]([]())]{<[]{}>{()<>}}}[<([]<>)<()>>({<>{}}[<
+([[([<{<[<((<(<>[])(<>[])>(<<><>><{}[]>)){<<{}<>>>({{}{}}<()[]>)}>[{{(<><>)(()<>)}[<<>[]>]}]>]<{{
+{{{((<<{[[{<([[]{}][{}<>])>}<[((()())<()<>>)[[[]{}]{[][]}]]<<<[]{}>{{}[]}>(<<>()><(){}>)>>](<
+{(([[{{<[[<{(({}<>)[<>[]])}<{({}{}){{}}}[[()[]](()())]>>]([<[{()[]})({<>}[<>{}])>{[{{}{}}{(){}}]{<{}{}>}}])
+{([(<{<<({[<[{()()}<[]<>>]{<[]{}>}><[[<>][()<>]]>]{<{{[]{}}<(){}>}[({})]>{{<{}{}><()<>>}([{}
+{{[[({{({[(([{{}()}[{}]]({{}<>}([][]))){({{}<>}[[]{}])<<()<>>>})]{(<[<{}{}>{<>()}](({}())((){
+{<({{<<{{([{{{[]<>}{<>{}}}((<><>)<()<>>)}[<[{}<>][()[]]><[<>()][<><>]>]]{{[[()<>]<<>[]>]<(<><>)
+<(<[(<<[[<<<[({}())<[][]>](({}<>)[{}<>])>>[<{{{}}<()<>>}<(()<>){{}{}}>>]>({{<[<><>](<><>)>[(<>{}
+[((<{[{{(<{[({{}[]}((){}))([[][]]{<>[]})]<{<{}[]>[{}<>]}[<{}()><{}<>>]>]>)}}]}{{{(<[(<{{()()}}>{[<{}<>><<>[]>
+{([<<{(<([[({{{}<>}<(){}>}<<()[]>{<>{}}>)((<[][]>[<><>])<<[][]>{<>()}>)]((<{<>[]}{[][]}>[[<>()]{<>[]}]]{{[
+[<{(<{([{{(([<<>()>]{<(){}><()<>>}){(([]{}>)<(<><>)>})}({({[<>]{<>[]}}[[{}<>]])}[{<[()[]]<{}<>
+{[(<(<{(<<[{[<[]()>(<>[])][{{}}[()[]]]}{{[[]{}]{()()}}<<<>>[[]()]>}]>{{<[<{}()>([]())]({(){}}(()<>))>([(<>(
+{{([[([[[<(({<{}<>>[<>[]]}{([]<>)<<>{}>})<{{[]<>}{{}<>}}([()()]<<>[]>>>){{[[()<>]]<((){})<[]{}>>}{<<[]<>><()
+<({([[[[[({[[{{}<>}({}<>)]({<>[]}[<>{}])][([<>[]](<>()))<([]())[{}{}]>]}(((({}[])[()[]])[{{}{}}(<>)])(<<<>
+[({{<{[([(((<{[]{}}{<>()}><[{}<>>{<>[]}>)){([<{}{}><()[]>]<([]{})[{}{}]>){{[[]]<[]{}>}((()[])[(
+(({<[<<{{[[<{(<>{})([]())}([[]{}]{{}()})><[<{}()><{}{}>]<<<>()>[[]()]>>]<[<<()[]><<>()>>[{{}<>}[<>]]]>]
+((<[[<{{{[({<(()[])<()<>>>})]{<(([()()][[]]))({[[]()]{[]<>}}{[<>()]})><<(({}[])[{}{}])>>}}}[[[{{{{[]{}}({}[
+([<[<{{{{[<<{{<>[]}([]<>)}><{{()[]}[<><>]}{<[]>[()<>]}>><{[{[][]}<()[]>]({[][]}(()<>))}<{(<>())(
+{((<(([[<[(<[{()[]}([]())>>[<[<>()]<[]{}>>(<()<>><[]>)])<(<{()}>(([]<>){<>{}}))<[[[]<>]{[]()}
+[(<[([([{{{<([[]<>]<<>>)[{<>[]}{{}<>}]}({(())[{}()]}[<{}<>>{<>()}])}([<[(){}]([][])><(()())

day10/main.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+"bufio"
+"fmt"
+"os"
+"sort"
+)
+
+func main() {
+fmt.Printf("Part 1: %d\n", syntaxError("input.txt", false))
+fmt.Printf("Part 2: %d\n", syntaxError("input.txt", true))
+}
+
+func syntaxError(path string, completion bool) int {
+var (
+score int
+scores []int
+)
+
+file, err := os.Open(path)
+if err != nil {
+panic(err)
+}
+defer file.Close()
+
+scanner := bufio.NewScanner(file)
+for scanner.Scan() {
+lineScore, leftoverStack := syntaxErrorScore(scanner.Text())
+if !completion {
+score += lineScore
+} else {
+if len(leftoverStack) > 0 {
+scores = append(scores, completionScore(leftoverStack))
+}
+}
+}
+
+if !completion {
+return score
+} else {
+sort.Ints(scores)
+return scores[len(scores)/2]
+}
+}
+
+// Given a string of parentheses, return the score of the string
+// if a syntax error is found, that is, an incorrect closing parentheses
+// pair. Otherwise, the score is 0 and any leftover characters are returned.
+func syntaxErrorScore(input string) (int, []rune) {
+var stack []rune
+pairs := map[rune]rune{
+')': '(',
+']': '[',
+'}': '{',
+'>': '<',
+}
+scoring := map[rune]int{
+')': 3,
+']': 57,
+'}': 1197,
+'>': 25137,
+}
+
+for _, paren := range input {
+switch paren {
+case '(', '[', '{', '<':
+stack = append(stack, paren)
+case ')', ']', '}', '>':
+if stack[len(stack)-1] != pairs[paren] {
+return scoring[paren], []rune{}
+} else {
+stack = stack[:len(stack)-1]
+}
+}
+}
+return 0, stack
+}
+
+// Given a leftover stack of parentheses, return the score of the string
+func completionScore(stack []rune) int {
+var score int
+
+scoring := map[rune]int{
+'(': 1,
+'[': 2,
+'{': 3,
+'<': 4,
+}
+
+for i := len(stack) - 1; i >= 0; i-- {
+score *= 5
+switch stack[i] {
+case '(', '[', '{', '<':
+score += scoring[stack[i]]
+}
+}
+return score
+}

day10/main_test.go

@@ -0,0 +1,52 @@
+package main
+
+import "testing"
+
+func TestSyntaxError(t *testing.T) {
+tests := []struct {
+input string
+completion bool
+expected int
+}{
+{
+input: "test.txt",
+completion: false,
+expected: 26397,
+},
+{
+input: "test.txt",
+completion: true,
+expected: 288957,
+},
+}
+
+for _, test := range tests {
+actual := syntaxError(test.input, test.completion)
+if actual != test.expected {
+t.Errorf("Expected %d, got %d", test.expected, actual)
+}
+}
+}
+
+func TestCompletionScore(t *testing.T) {
+tests := []struct {
+stack string
+expected int
+}{
+{
+stack: "[({([[{{",
+expected: 288957,
+},
+{
+stack: "((((<{<{{",
+expected: 1480781,
+},
+}
+
+for _, test := range tests {
+actual := completionScore([]rune(test.stack))
+if actual != test.expected {
+t.Errorf("Expected %d, got %d", test.expected, actual)
+}
+}
+}

day10/test.txt

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