Day 10.

input/10.txt

@@ -0,0 +1,102 @@
+[<[{<[(([<[[{[()()]}]{<<<>[]>[()[]]>{(<>[]){<>[]}}}]<{(<()<>>{()<>})(<()>)}([{()[]}](<()<>>
+<[(<({[<(<<({({}[])[<>]}[<<>{}>[()()]])>>)>]})>{[([({[{{<[[]{}]{{}}><{()[]}[{}]>}}{{[<<>()>((){})
+{<({([<([[<<[(<>())({}{})](<()()>{{}})>(([[]{}]<[][]>){<{}>{<>{}}})>]][[((<[<>()]<<>[]>>{{()[]}{[]{}
+([{({<<{<<<{([{}[]]([]())){[(){}]}}{[<{}()>(<>[])]}][({[()<>][<><>]}{{{}[]}})<<<{}()>>>]>([[<[{}<>]
+{([{({(<{[<(<(()()){{}()}>[(<><>)<<>[]>])[{{{}()}[(){}]}[<()[]>[{}[])]]>{([{{}{}}{[]}][{{}<>}{<><>}]){[[[]()
+[{(([[{([(({(<{}()>({}<>))((()())(<>[]))}{<{{}[]}[{}()]>{{()()})})<{{([]{})[<>[]]}[{<>[]}{
+<<([{{({{{[(<[<>()][()<>]>)]}<(<<<<>()><{}()>>><({{}<>}{()[]}){<(){}>}>)>>})<[{[<([[{}{}]{{}()}]
+<[{{[<[{(<<([([]{})]<[[]{}]{<>()}>)(<<<>{}>{{}[]]>(<[]()>(()[])))><<[{[][]}{[]}](([])([]))><({{}{}}{[][]})
+{{{({{{([<<<{[()]({}{})}((()[])<()<>>)>{{<{}<>><{}()>}}>(<<(())({}())>{{{}}({}())}>{<[{}<>]<{}{}>>[{<>()}
+{<({<[{[<<{{[[[][]][<><>]](([]{})<()[]>)}<<((){})><[[][]](<><>)>>}{(<<{}<>><<>>><((){})([]<>)>)<(([]))(
+({{{([({<((<<<()>[[]<>]>(<<><>>(()()))>))>})]){({[<[<<[[{}{}]][([]<>)]><{<{}()><()<>>}(<[][]>[{}()])]>{({{
+(<{<<[[[(<{<({<>()}{{}<>})<<()()>(<>[])>>(({{}()}([])))}>([[<({}())({}())]((<>{})<<><>>)][[<(
+[([({{{[<([<[(<>[])[{}[]]]<[[]{}][<>]>>])<(((<()<>>(<>{}])({<>{}}[{}<>]))<([()()]{[]<>})({<>()}[{}
+<(<<([{{[<((({<><>}<<>>)[[[]<>]({}())]){(<<>()>{[]()})[<()>{[][]}]})>]<[[[{(<>{})<(){}>}[{<>{}}]]]][
+{[[[{[(((<{[{([]{})[[][]]}(<{}()><<>[]>)][<[<>{}]>]}>({([(()())<[]{}>](([]{})[<>{}])][[{[]{}}<<>{}>]({{}}[<>
+{{{([[<[({<<<({}{})<[]()>>[[<>[]>{<>[]}]>[({<>[]}({}<>))[[[]()][()<>]]]>})]>]<(<<<<[<((){})<{}{}>><{()()}((
+[{<<<[((<{{{[<{}{}>[{}{}]]([{}<>]{{}<>})}{{[{}{}][{}]}({[]<>}{<><>})}][([<[]<>><{}<>>][<(){}>(()
+[{<(<[{(<(<((((){})<[]<>>)[{()<>}{[]<>}])><(((<>)(<>[]))(<[]<>>))([<<><>>[[]<>]]{<[]()>{()[]}})>){<({{[][
+<(<<<[([[<{{(({}[])[<>{}])<(()<>)({}{})>}}>{{([(<>())<()[]>]{{[]<>}})<[[<>()]](<()[]>)>}<{[<{}<>><{}[]>](
+{((<[<[<(<[({{{}<>}(()<>)}{(<>{})[[]{}]})(((()[])))]>)[{([([<><>][{}[]])[<()[]>(<>[])]]({[
+[({([<([({<(<<(){}><{}<>>>{{<>[]}[()[]]})[[[{}[]](()())]]]({[{(){}}{()}]<{{}()}{{}()}>}[([[][]][()[
+({[[{[[({{[[(<<><>>{()}){[()()]}]<{{<><>}({}())}{{[][]}{()()>}>]<[{<<>[]>[[]<>]}]<[<()[]><(
+(<[{[(<{(<{{[{<><>}{[][]}](<(){}><[]()>)}}><{<(<<>()>([]<>))<({}<>){{}()}>>}{([(()[]}[<>[]]])<{{[]{}}
+<{{(<([(<<<<[{{}<>}(()[])][<{}[]>[<>[]]]><<{[]()}(()<>)>({()<>}({}[]))>><[(([]{}))[{<><>}([][])]]{{(<>())}(
+{<[(<{[[(<<[{<(){}>{<><>}}((()<>){<>()})]<[[{}<>]{{}[]}]{([])([]{})}>><{(<{}[]><()<>>)}<(({}()]{[
+[{[([([{{{{([(()[])[()()]])[[(<>{})[{}[]]]]}}}{<({[<()[]><{}()]]}{[[[]()]{()()}]})<<<[{}<>](<>[])>[(()<>)([]
+{(<{([<<<((({[{}<>]({}())}))[{{((){})[()()]}<{{}<>}<()[]>>}{{{[]()}}}]){((((()())(())){(<>{}){{
+{<<{{{([[<{<<[{}<>][<>[]]>>(([()()](<>[])){([]{})})}>{<((<<>()><[]<>>)({[][]}[[]{}])){(<(){}><{}>)(
+[[[{[{{{{[<{((<>())((){}))(([]{}){()()})}>([[[{}{}]{[]()}]{(()())<{}[]>}][{((){})<{}[]>}<<[]><
+(<[[<[{[<(<[<<{}[]>[[]<>]>((()<>)[<>[]])]{[[{}<>]({}{})](<[][]><[]{}>)}>([{(<>[])<{}{}>}({(){}}[()<>])]
+{{<[{({([[(([[{}<>][{}<>]][[<><>]]))<([({}()){[]()}](({}())<{}<>>))>]<{<(({}{})[[]<>])[<{}{
+[[({(<[<<{<{<({}())(()[])><((){})[()<>]>}{{<()>(<>[])}}><[([[][]]<()<>>)][<(<>())[()()]>{(<>())}]>)>((<<[
+[([{<<[(([((<<()[]><{}[]>>[{<>()}<()[])]){[{()[]}{<>[]}]{{<>}(()())}})<[(({}{})(()[]))(<[]
+((<<{{{<<[{[<<[][]>[<><>]>(({}<>)(<><>))](<<[]<>>(<>[])>[<<>{}>((){})])}]>>(({{([<<><>>{{}
+([<(([[[((<(([<>()]<()<>>)<[[]()][{}()]>){<(()<>){()()}>}>{(<(()()){{}<>}><<[]<>>[(){}]>)[<<{}{}>{[]
+({[<<[{<{<<<[<{}[]>]{[[][]]{[]()}}][{<<><>>(()())}({{}[]}<{}[]>)]>>((([<{}{}>({}())]({{}()
+{{[<<<[{(([<[<(){}><<>[]>]({<>[]}[<>{}])>]([<[[][]][[]{}]>({[]<>}[()<>])]))(([({{}()}{<><>})[[()()](<>[]
+[([{(<[<([[(<(()[]){(){}}>)[[<[]()>([]())]({[]<>}<{}()>)]]([<{[][]}(()<>)><[{}[]][()[]]>]<[<{
+(<[([<<<(<[({(())(()[])}<{<>()}{{}()}>)[[{()[]}<<>[]}]{[<>()][{}{}]}]]>{{[({<>[]})][([[]()]<{}<
+[[[<<{({[{{<[[[]()]<(){}>]{([])<()[]>}>[[({}[])[[]<>]][<(){}>[()<>>]]}{<(<[]()>{{}<>})<(<>[])({}
+<{[[<[[{[[(<<{(){}}({}<>)>({{}()}([][]))}([<[]{}>(<><>)]))<{{<[]<>>(()<>)}([[]()]({}[]))}({[<>{}
+(<[<[{{([{(<[[()()]]{{<>()}{<><>}}>(<[()[]]{[][]]>({<><>}<<>[]>)))((<<()[]>>)[[<{}[]>]<[{}()]<{}<>>>])}[
+{{{[<{[((<([<{(){}}{{}[]}>{[(){}][{}{}]}])<<[<<>[])(()())][((){})]>{({()[]}[[]{}])}>>){[({
+{(((<(<{(<<((<[]()>))({({}<>)({}<>)})>>)}>)><[[<[<[[{(<><>)({}())}(({}<>){()[]})]]{{[{<>{}}
+{{(<<(<([({(({[]{}}{{}[]})<(()())[()()]>)}<{{[{}<>](<>{})}{{{}()}{<>{}}})(({{}{}})(<[][]>{{}()}))>){[<[{<>()}
+[(<{<([[[<({[{<><>}{<>{}}][{()<>}{<>()}]}<(<()[]><()<>>)>)><<([[{}{}]]([<>[]][[]<>]))(<<<>()>[()<>]>
+({<{(<{[(<<(<([][])[(){}]>{({}<>)[{}[]]}){(({}[])[()()))(<[][]>(()<>))}>>)((<(<({}[]){[]()}>){({<>()}[{}
+{<[([<<[(<{((<{}<>>)(<{}[]>{{}[]}))}(<[<[]()>([]())]{[{}]<<>[]>}><[{{}<>}[{}[]]](([]<>)<{}{}>)>)>){
+[(({<([(<<[<<[[]<>]<()()>>{({})([]{})}>]<[{[<>()]{[]<>}}{{{}<>}<<>()>}]>>>((<{(<<><>>{[]{}})({<>[]}((){
+{[[([[{<<[[[<[<>{}]{<>()}>({{}()}[()<>])]]({{<{}[]><<><>>}{<()<>>}}{{{[]()}<()<>>}<(<>[])(()[])>}
+{<{<{{{{[[[((<{}{}>{{}{}})<{{}{}}{(){}}>)[[(()<>)]]]({{([]())[<>[]]}}[{<[]<>>((){})}([[]<>])])]
+<[({({[[<(<({([]<>)[<>]}[[()[]]([])])<(<(){}>(()[]))[<<>()>[[]{}]]>>>><{[{<[{}{}][{}()]>{([]())[<><>]}}<{<<
+[{<([<[(<({[<[<>]<{}[]>>{({}<>)[[]<>]}]{{{[]<>}(()[])}<(())>}}[({{[]()}{{}{}}}{{[]{}}[()[]]})])<{({{(){}}
+{{([(([{{{((<[()[]][<>{}]>[<<>()>[[][]]])<{<{}>[(){}]}{({}())[()()]}>)({({<>[]}<[]()})<({}{})<<
+(<(<{([<((<{<<{}<>>[()()]>({[]<>})}([[<>()]([]())])>{([{{}[]}(<>[])]{[[][]]{[][]}})}))>(<[{
+[({{{(<[{{{<(<{}>)<{<>()}<(){}>>>[[{()()}(()<>)][[[][]]([][])]]}}}((({((<>{}){{}{}))[{{}<>
+[<(([(<[{[<<({(){}})([<>[]){[]()})>>([[<()[]><{}>]])]<({[{()<>}<[]<>>][[<>()]]})>}]>)]{<{<(
+([(({({{{[[{(<[][]><{}<>>)}[((<><>)(()<>))<{<><>}{<><>}>]]{(([{}<>][[]()])<<[][]>([]())>){<[(){}]>}}][(<<
+({(<{<({{{<(<<[][]}>[{[]<>}{[]{}}])><(<(<>[])([][])>{({}<>)}){{<[]()>(()<>)}}>}(<<<<{}{}>[(){}]>[[()[]](
+<[<((<{{{<<{({<>[]}){<[][]><[]<>>}}{[{[]()}[{}[]]][({}())]}>[{<[()<>]>[{()[]}((){})]}(({[]()}
+[<({{[([([<{<[[]]<{}{}>>{([][])[()<>]]}[[<(){}><(){}>]]>((((<>{})[<>{}]){(()[])}){<[<>](()<>)>([[]<
+<[[([[[(({{<(({}){[][]})[[<>[]]([]())]><[<{}{}><{}()>]>}<(<{<><>}{()[]}>([{}()]((){})))>}{{([{{}}{<>[
+([[{<<<<(({(<([]{})<{}[]>>)}([[<{}()>)([[]{}]<<>()>)]{{{(){}}}[<()<>>{<><>}]}))<[{{<()()><{}{}>}}][{{<(){}><
+{[{{(<{{{<([[{{}()}{{}{}}]]({<[][]>(<>[])}[[[][]]{<>[]}]))>}}}>)}}{<[<{[{[<[({[]}<[]{}>){(<>{})(<><>)
+<{{([<{{{{<{{{()[]}{[]()}}{(())((){})}}{{(()[])[{}<>]}(<()<>>([][]))}>}}<[{({<()[]>({}[])}
+{(<([(([{{{({[()()]<()>}[([]()}<<><>>])[{[<>[]]<<>>}{{[]<>}(<>())}]}}<{{[[{}[]]]}(<<<>()>>({[]()}<<>[]>)
+<[{{{[{(<<(({<<>[]>{[]}}<{{}[]}<{}[]>>)[[([]())(<><>)][[[]()]([]{})]])[<{(()[])<()>}>([{{}{}}]{<(){}>(()())
+[(<[({<{[[{<{[{}[]]{[]<>}}[<()<>>[[][]]]>(<[{}<>]({}())><[{}{}]{()()}>)}((<<<>[]>(<>{})>[(<>())[{}{
+[[<{{<<[<<<<({{}<>}<{}[]>)((()[])[[]<>])><([<>[]]([]<>)){(<><>)}>>[({{()}{<>[]}}[([][])[{}[]]]){([{}()][<>{
+{{{<({[([({<[[{}<>](()())]([<><>]({}[]))>}(({<<>()>[[]]}[<()>{<>{}}])))]<{({{(()())<<>>}}[({[]{}}[
+(<<{(({{(<{{[<{}{}><<>()>]{{()[]}<<>{}>}}(<<{}<>><()>>{<()<>>([]{})})}<[{([]<>)<<>[]>}[<{}()><{}>]]>>
+{<[[<{[{(<{<<(<>)<{}{}>>>[<<{}()>({}{})>]}<<[({}[]](()[])]{<[]<>>(())}>{<{()<>}({}<>)>{<()
+[{((<<{<{[{[([()<>](()())){(<>())}}([[()<>][{}()]][({}[]){[]()}])}([<[()<>]([][])>[[[]{}]{()[
+[<[<[<<[([<{[{()<>}({}())]<{{}<>}([]())>}(<<<>{}>[{}{}]>[[[]()]])>]<({({(){}}<[]{}>)([()<>](()))}[({[
+[<[<[(((<(({{([][])}}<[[[][]]{(){}}>(<()[]>[[][]])>){([(()<>)<()()>]<[{}()]([]())>)<<{<>()}>([<>[]]{[]
+{{<{<[{[{[(<([{}()]{[]<>})({<>})>(({{}{}}([]{}))))<[[({}{})<()[]>][{[]{}}{(){}}]]{([()<>])(<()[]><<>()>)}>]}
+((({([{(<{<[[{{}<>}<{}()>]{([]<>)[{}[]]}]>(<([[]<>])((<>[]))>{<{[][]}(<>())>{{{}()}(()[])}})}>{[
+<{(([(<<<(<({{[]<>}{<>[]}}{[[]{}][[]{}]})>[<<[{}<>](()<>)><(()<>)[{}()]>>(<{<>[]]({}[])>{(<>)<[]{}>})]){[<<[(
+<{<{{<<<{((<([()()])(<(){}>{<>()})>)<([([]()){{}[]}]{{{}}<{}[]>})(<{()<>)>[<{}()>])>)(<(([()()](
+(<[{(<(<[<<[((<>[]){<>[]})<(<>[]]({}{})>][[{[]{}}{()[]}]]>>[<{(<[][]>{{}{}})}<([()[]]<[]<>>)[{<><>}<{}{
+({{<<({<<[<[<(<><>)<()<>>><[()<>]([][])>]>[{{<()<>><()<>>}}(<{{}()}><{{}{}}<{}{}>>)]]([[[{[
+([[<<([[<([{([()[]](<>[]))<<<>[])({}[])>}[{[[][]]}]])[<[[({}{})<{}<>>]]([{{}<>}({}[])](([]())({}{})))>[[
+<{<(<{({[({[[[()[]]{{}[]}][[<>[]>{<>[]}]]})]<{[{<[{}[]]{<>()}><([]<>){<>{}}>}{(<(){}>{<>{}})
+<<<[<{(<{(({({<><>}{{}<>}){([][])([][])}}[<{(){}}<<>{}>>{([]<>)[()[]]}>)<{{{<><>}{<>{}}}{(
+<[<<(({<<[<([<{}()><<><>]])<[[{}<>][<>{}]]<[{}<>](<>{})>>>](<(<[[]<>][(){}]>(<<>()>{<>})){[({}[]
+<[[{<[([[[[{([()<>])<[[][]]{[]{}}>}](<[(<><>)]>({{(){}}<[]()>}))]]]{<({{(<<>()><(){}>){<[]<>>}}}[[
+<{[[[(({{[{(([{}()][<>()]))[([[]{}]<{}[]>)([<>[]]{{}{}})]}[{[(()[])]((<>{}){()()})}<<{(){}}[[]<>
+(<((<[[{((({((()<>)){{{}<>}(<><>)}}<((()[]))>)([{(<>[])([]<>)}[([][])(<>[])]]<<<<>{}>>[([][])[{}<>]>>))([<
+[(((<[<{[([{(<<>[]>((){}))[[[]()][<>{}]])]<({<{}>{[][]}}{{{}<>}[<>[]]})<<{{}()}{(){}}>({<>{}}{{}[]
+{((<[{[<<<[{<[(){}]({}{})>}<[<[]{}>({}<>)][{(){}}<<>{}>)>][<[[{}]({}[])]>]><[{{{{}[]}}({[]{}}(<>
+[[<[(((({[[[({<>{}}{{}()})[<(){}>{<>}]]{(<<>{}>(()<>))([[]<>]<()<>>)}](<([[]{}]<()()>)>{<[()
+[<<<[{[<{[(({([][]){<>}}))(<{([]())[{}()]}[[{}[]]{[]<>}]><{(<>())<[][]>}[([][]){{}()}]>)](
+<(<{<<[([[<{[[<>()]<{}{}>][[(){}]<<><>>]}>]{(([[<>[]](<>{})>{<()[]><[][]>})[<[(){}]{[][]}><[<>()]([][]
+<[([<<[{{[<<<{<>()}[<>()]>[<{}{}>[{}{}]]>[{[(){}]}([[]{}])]>]}}]>>{<([<(({({[][]}){([]()){{}{}}}}
+[({{{((<{<{[<<{}{}>><<[]{}><<>{}>>][<{{}()}>]}[(<[[]]<<>[]>>[([]())<<>{}>]){<[{}[]]>((()<>)[[]{}
+{[<[[(({([[<[(<>{})<<>{}>]{<()<>><{}[]>}>[[{{}<>}([]<>)][({}())([]())]]]])[[({{[[]<>][<>{}]}[[<>
+(((<[[<<{{[[[([]{})<{}<>>]]{{[<>[]]<{}{}>}({<><>}{()()})}][[<<[]()>{<>[]}><(()())<()[]>>]{{([](
+[<{<[[[<<{[{<({})([][])>[{[]()}]}<[{{}()}[<><>]]>][((<[]{}><{}()>)(<<>()>))([<<>()>((){})>)]}{[({(<>())<(
+{([<[{{{<[{[({<>()}(<>{})}[{()()}[<><>]]]}<{{{<>[]}[{}[]]}({[]()}[{}()])}<({()()}<<><>>){{{}{}}
+{{<[[<({([{(([[]<>][{}<>])){{({}{})<<>()>}}}[[{[<><>][{}{}]}<{[][]}([]())>]<<[()[]]{()<>}>{<{}[]}(()())}>]
+<({<[([{[[<{<{[]{}}[<>]>}>([(<()[]>[[]<>])<{<>[]}>]{[(()())[{}]][<{}<>><{}>]})]]([{{{([]{})[(){}]}[<
+[<<[{[{{[[{[[[()<>][()[]]](({}<>)[()<>])]<<(()[])>([<>[]]{()<>})>}([<[{}{}]>{({}<>){[][]}}][{[<>[]][<>]}])]]}

lib.rkt

@@ -139,7 +139,7 @@
 
 ;; median : (listof number) -> number
 (define (median ns)
-  (list-ref (sort ns <) (/ (length ns) 2)))
+  (list-ref (sort ns <) (floor (/ (length ns) 2))))
 
 ;; ≠ : number -> number -> boolean
 (define (≠ n1 n2)

src/10.rkt

@@ -0,0 +1,35 @@
+#lang curly-fn racket
+
+(require "../lib.rkt")
+
+(define input (map string->list (problem-input 10)))
+
+(define (corrupted-score char)
+  (assocf char '((#\) . 3) (#\] . 57) (#\} . 1197) (#\> . 25137))))
+(define (incomplete-score char)
+  (assocf char '((#\( . 1) (#\[ . 2) (#\{ . 3) (#\< . 4))))
+
+(define (autocomplete-score stack)
+  (for/fold ([score 0])
+            ([char stack])
+    (+ (* score 5) (incomplete-score char))))
+
+(define-values (part1 part2)
+  (for/fold ([corrupted 0]
+             [incomplete '()]
+             #:result (values corrupted (median incomplete)))
+            ([line input])
+    (let loop ([stack '()]
+               [line line])
+      (match line
+        ['() (values corrupted (cons (autocomplete-score stack) incomplete))]
+        [(cons char line)
+         (match* (char stack)
+           [((or #\( #\[ #\{ #\<) _) (loop (cons char stack) line)]
+           [(#\) (cons #\( stack)) (loop stack line)]
+           [(#\] (cons #\[ stack)) (loop stack line)]
+           [(#\} (cons #\{ stack)) (loop stack line)]
+           [(#\> (cons #\< stack)) (loop stack line)]
+           [(_ _) (values (+ corrupted (corrupted-score char)) incomplete)])]))))
+
+(show-solution part1 part2)