Day 10

Cargo.toml

@@ -38,3 +38,7 @@ path = "src/day8.rs"
 [[bin]]
 name = "day9"
 path = "src/day9.rs"
+
+[[bin]]
+name = "day10"
+path = "src/day10.rs"

inputs/day10.txt

@@ -0,0 +1,90 @@
+(((<(([{{((<[[<><>]<()[]>]{[{}()]<(){}>}>[<([]{})>])(<<(<><>>[<><>]>(<{}()><(){}>)>[(([])<[]()>)])){<((<{}()
+{(({({<[[[{[{({}{})[[]{}]}[{(){}}((){})]][{((){}){[]{}}}<(()())<<><>>>]}]]]{([<{<<()()>([][])>({[]()}[{}<
+[[{<(([<<{(<[[()()]]{[[]()]<{}>}><{{{}()}<<>[]>><(())[()[]]>>)([{[[][]][()()]}{{()()}}](<{{}()}>))}[([{<<
+{<[{<{[({[[[[{<>{}}<{}()>]<{<><>}{[][]}>](<<<>[]>[()()]>[{[]{}>[<>()]])]{{{[()()][<><>]}<[{}()][{}{}]
+(<[{[{[((<{[[<()()><{}{}>][(<>{}){{}{}}]]{<[<><>]>{{{}[]}(<>[])}}}(<[[[]{}](<>{})]{[[][]][[][]]}>)>)){<{
+<<<(<(<[[[<[{{[]<>}([]())}([[]])]([[[]<>][()()]]{<()()>([]{})])>]{[[<{[]{}}([]{})>{(<>[]){{}{}}}]]{({{<>[]
+[{<(({(<{<{<<{<><>}>({<><>}<<><>>)}{[{[]<>}[[][]]][<()<>>]}}<[[[()()]{<><>}]((<>)[{}()])]{<{()<>}
+<[([{{{({<({(<(){}><[]()>)((()())[[]()})})[<{<<>>((){})}<[<><>]{(){}}>>{{(<>[])({}[])}(<()<>>)}]>})}({{({
+{[{{(<[[[<(((([]())[[]<>]){(()())[[]<>]})[{([]<>)[<><>]}<({}{})>])>{[(<<<>{}>(()<>)>)]<{([<><>]<[]()>><<{}[
+(<<[<({[(<{[({<><>}<{}<>>)]}<<([<>[]])(<{}{}>[[]{}])>>>(([{[<>[]][{}[])}<(<><>)({}[])>](<<()
+{{[<(((<([{(<[<>{}]({}())>){{[{}]<[][]>}[{<>()}{<><>}]}}][<<{<[]<>>[{}<>]}[<{}{}>]>[<[[]<>]<()()>>[[[]
+<<<([([{{<({[{[][]}[{}<>]]}<[(()<>)[{}<>]]>){{{[()<>]}(<<>>({}[]))}(([[]()][[]{}])<([]<>)[<><
+({[[[([[([<{<{{}()}{<><>}>}>])[{(({([][])[{}()]}{(<><>)[[][]]})<<<{}>[{}[]]>(({}())<()<>>)>)
+<[{[[[<({<<[{<<>>{{}{}}}{[()[]]}]<[<[]<>>{<>{}}]>>>((<{{[]{}}{<><>}}>[{({}{})<{}<>>}]))}[({
+<({[<{(([[[{<<()<>>((){})><{()[]}<{}()>}}[([<>{}][()<>])]]<(([(){}])<{(){}}[[]()]>)<{[(){}](<>[
+[<<{{[<<{[<{({<>[]})({{}<>})}><<<<()[]>(()<>)>>[{{[][]}[[][]]}((<>)<<><>>)]>][(<{[[][]]<[]<>>}>(<((){}){[]<
+({[({(<{<<<<{({}())(()<>)}><({{}[]}<<><>>){[{}<>]}>>]<((([{}{}]<[][]>)({[][]}<{}()>)))<<{[[]<>][[]()]}{<<><
+<[<<([<[(<<{[[(){}]<[][]>]<({}<>)[(){}]>}<[({}[]){()()}]({{}[]}[()()])>>><(<({{}<>}{[]()})[(<>
+[[[([<<[<[<{[[(){}]((){})][(()<>)<()>]}(<{[]{}}{[]}>)>]{{[{{<><>}<()<>>}{[(){}]<<>{}>}]([[[]<
+((([[[{<{[<{[{<>{}}]}({<[]>[{}{}]}<({}{})([][])>}>(((({}{})<{}()>){<<>{}>{{}<>}})(<{{}<>}{{}}
+[<[{[({<[({{{<<>{}><()[]>}}{([<>()]{{}[]})({()[]}[<>[]])}}[{(<()[]>([]{}))<<()<>><[]()>>}{[<<>
+<{{([({<{([<<(()<>)[[]{}]><{()()}<<><>>>>]){{<{{()()}<()<>>}>[{(<><>)<[]()>}]}[((<{}()>){[()[]]{()()}})]
+<{[([{{[[[<<[<()<>><[]()>][(<>())(()<>)]>(([{}{}]([][])){<[]<>>([]{})})>{[[<{}[]>((){})]{<<>
+{[<([{({{({({[[]()]{(){}}}<([]{})[<>{}]>)<<[()[]]>([()[]])>}{[(({}<>)<()()>)[{(){}}<{}{}>]]}>{[[{
+<<({{<<{<[{[{({}{})[()]}(<{}{}><[]()})]<{[[][]]({}[])}{(<>{})<()[]>}>}<[({{}<>}{<>()}){({}[
+([[[<<{<([[(({<>()}{[][]})[[()<>][()]]){{{()[]}(<>[])}<([]<>)[[]<>]>}]])>{(({{{[<>{}]{[][]}}}}<[(({}[])<<><>
+[<(({<[[{([{<<()()>(()<>)><<[]{}>{()<>}>}{<<{}>>{{[]{}}<()<>>}}]{<{[{}<>]([][])}}<{[()()][{}]}>})(([[<{}
+<{(<{(((<{<<(<<>>{<>{}})[([]<>)(()[])]><[([]{})((){})}<<{}[]>(<><>)>>><{{{<>{}}(<>[])}{[()()][()
+<{<[<<[({<[[<{{}[]}><({}{})({}[])>]]<[<{{}<>}>]({[{}]{<>[]}})>>[<(([{}<>]){<<>[]>[<><>]})[(<{}()>{[
+(([[(([<<(<(<{()()}(<><>)><(<>{})<[][]>>)[<((){})<{}{}>>{{()()}{<>{}}}]>[<<<()()>(<>[])><(()[
+<{({{({<[(<{<(<>{})<<>{}>>(({}[]))}(((<>())<{}<>>)(<()>))>([[([]<>)<{}[]>][[<><>]<(){}>]][{<(){}>(
+<<{(<(({[<<{[(<><>)[<>{}]]{<[]()>({}{})}}<(<{}[]>)[{<>()}<[]<>>])>>]{((({(<>[]){()<>}}[{[][
+(([((<([[([<[{[]{}}({}[])][<{}{}>[()[]]]>(<<{}[]>>)])([{(<[]{}>([]<>))}<[{<>}[{}<>]]([(){}][{}[]})>]
+(([{(([{[<{<<<[][]><()<>>>(({}[]){{}<>})>}({{<[]()>({}[])}([(){}][{}<>])}(([[]<>][[][]])[{{}()}<<>
+([(<<([{<[<(<<(){}>{[]()}>((()<>){[]<>}))[{([][])}<[<><>]{{}{}}>]>(({(<>[])[(){}]}(({}[])<<>()>)))]>{{[{[[
+{(((([<{({[(<[<>[]][[]]><(()[])[[][]]>)]({{{(){}}[<>[]]}((()[])<[][]>)}{{<()<>>([][])}<{()>>})}<<(({<
+<[({<<{{(({<{{[]{}}(<><>)}<[()[]]<{}()>>)<<{{}[]}>([()[]]({}{}))>}){({{[(){}][<>()]}[[()()][()[
+{<([[{((([[{([[][]]<()<>>)<[<>{}]<{}()>>}]]((<[([]{})[<>()]][<[]>{<>}]><({{}<>}{[]()})(<()()>(<>{}))>)))){(([
+{(([{([{((({[{()[]}((){})]{{[]()}[()()]}}<<<{}[]>>({()()}{[]()})>)((({<>[]}[<>{}])(([]{})))[[{()[]}{<>{}
+(<(<[[(((<[<<{{}[]}[[]{}]>[{()[]}<(){}>]>]>)[[([[{()<>}<<>()>]<({}{})<{}{}>>]){{[{<>[]}{()()}
+(([[(([(<{([[<()()>[{}{}]][<[]{}><[]()}]]{<<{}<>>>})[[{([]())<[]()>}[<{}{}>[<>{}]]][((()())([]()))([[]
+[<([<{({({[[({()<>}[{}{}>)]{([{}()]{{}})[[[]{}]<{}{}>]}]})<{{{{(<>)([]{})}[<[]()><{}{}>]}}{{<[{}()]{{}
+<([{[([<(([[(<{}()>([]{}))({{}}(<>()))][{(()<>]([]{})}[[[]<>]{()[]}]]]((<[[]<>][<>]><{{}{}
+<<([[<{[[([[{<[]<>><[]{}>}][([<><>]([]()))<[()()]([]<>)>]][[<[()<>][<>[]]>({<>{})[<>{}])]<
+<{([[(<(({{<({()}[{}[]])(<[]<>>)>}{{[([][])({}<>)]<<{}{}>{<>[]}>}[[[[]()]({}())]((())[[][]])]>}(
+{[[{[<[<<(<{<(<>()){{}<>}>}[<<{}[]>[[][]]>((()[])[()()])]}[{<{{}{}}[{}{}]><[[][]][(){}]>}[[[<>{}]<
+{<<{[(<{{[[([<[]()>{{}()}][{<>{}}[<>()]])]({(<[]{}>){{[][]}([]())}}<[[<>]<<>{}>]<{[]()}({}{})>>)](
+[<[[[{<[{[(([{<>[]}<{}<>>][{()<>}[[]<>]]){([[]()]<()>)<[{}{}][{}{}]>})[((<{}{}><<>()>){([]<>]<[][]>})({<<
+{<(((<{<{{{<[([]{}){[]{}}]<[[]<>][<>()]>>(<[<><>][<>{}]><[(){}][()()]>)}((<{{}<>}<()[]>>{{[]{}}{
+(<<[[[[{[{{(<(<>{}){[]}>{<[]<>>([][])}){{([]())(()())}}}}){[[{(<<><>><()<>>)<(()[])<{}()>>}]]}}({[(<{[[]()
+{({(<{<<<<((<[()<>]((){})>)){<<{<>}([][])>>(<<()()>([]())><[{}{}][{}<>]>)}>>([([[[[]<>]<[]()>]{<()[]><<>()
+<{[(({{([(({<<[]<>]>{<<><>>[<><>]}}<(<()()>)[(()<>)]>){[(<{}{}>[{}<>])]})]{(<<[[[][]]([]{})]>>)[<([[()]
+{({{<(<<{[([((()<>)<{}<>>)<[<>[]]{{}<>}>](<([][])(<><>}>))[[([[]{}][<><>]){[{}()]({}{})}]<([{}[]]{<><>}
+<({[(([[[<<((([]{})<()[]>)((<>)<[]>))(<({}<>)[()()]>[([]<>){{}<>}])>[{[([])([]())]<[()()]<{}<>>>}
+{{{[[<{{{[[[(({}[]))]{([{}()][[][]])[[[]<>]([]<>)]}]]((([[<>]{[]{}}]<[<>()]<(){}>>)({[(){}][
+[{{([{{<(<<({[(){}]{()()}}[[[]{}]<<>[]>])>>[<<<{{}()}({}[])>><(<()()>(()()))({[]{}})>><{({<>{}}{<>[]})[<{}
+<<<<{{<<[[<[((()[])<{}{}>)<(()[])({}())>](({<>}{{}[]}}{[(){}]{()<>}})>({(<{}<>>(()[]))<<{}[]>{{}[]}>}<{{[][]}
+<<((({[{[{<([([]())<()()>][<{}[]>([])]){({()}<()()>)<([]())(<><>}>}><<<{{}<>}[[]<>]>[[()](<><>)]>
+(<{[[[[([([[<{<>{}}<[]()>>{<<>[]>}]{((<>{}){[]<>})<(()())([]{})>}](<[([]<>)(<><>)]{<[]<>>(<
+[{<(<<<[(<{<[[[][]](<>())][<{}{}><{}()>]><{<[][]><<>[]>}{({}<>)}>}<<[({}())([]())]<<{}{}><()<>>>>[(
+[[([({[{([[(<[(){}]<[]{}>>((())(()()))]]((({<><>}(()())){{{}()}}){{[<>()]{{}()}}<[[]<>]<{}()>>})]<(({<[][]>
+<<{[(<({{({(<{{}<>}(()<>)><{[]{}}[[]{}]>){[<<>()>{{}}]((()[])[[]{}])}}[((({}<>)[()()])<[{}[]]<<>[]>>
+[<{<({{({{{({{()[]}[()[]]})<{(<><>)[()<>]}{{<>{}}}>}<<{({}{})({}<>)}[[()<>][[]{}]]>[([{}[]](()))(<<>
+{{({{{[[[(<[<{<>()><{}[]>>{<[]<>>[<>]}]>[<<[<>()]([]{})>{(<>)(<><>)}>(<(<>{})([]<>)>(<(){}>[{}[]]))
+<{[{[{[(<<({[({})([][])][[(){}]([][])]}<{<{}<>>{[][]}}{((){}){{}{}}}>)[<{[[]{}][{}{}]}({()()}([]{}))>[[[<
+({<<{[<(({[[([[][]])[(<>[])[{}()]]]<{<{}<>><[]<>>}<({}{})<{}()>>>}(<(<()[]>[{}[]])<([])<<>[]>>>{<[<>()]
+<<{<{{([(({([{[]<>}[{}{}]]([()()][[]{}]))}[<{{[][]>{{}[]}}{[<>[]]{{}()}}>{((()<>)[(){}])}]))][({[<(<[]
+({<[[{((<[[[({<>[]}{[]{}})({{}[]][<>[]])](({()<>}<{}[]>)(({}<>)<[]<>>))][<<<(){}>>{(<>{}){(
+({(((<{[([{[(([][])([]<>))[{[][]}<[][]>]]}((<((){})(<><>)>(([][]){<>}))([({}[])<[]()>]{<<>[]>{(){}}}))]({<<
+([[[[[([<<{<[<[]<>>([]())]{{<>{}}<<><>>}>[<[()[]][[]<>]>({<>{}}<()})]}[[[(()[])({}())]]((((
+([(<<{<(<{<{[[<>]]<[<>[]]({}())>}><<{(()<>)(<><>)}{(<>[])<{}[]>}><<[<>()]<<>>><{{}{}}>>>}>)>}>{{
+({<<{([({{([{{<>}({}{})}([[]()]{[]()})][{<<>()>([])}<[[]{}]}])(([[[]{}]{()[]}]([{}()]<()<>>))
+(<{<[{[(<{([(((){}))[((){})<()()>]]{{[[][]]<(){}>}((<><>)<[][]>)})}{((<([]{})<<>[]>>{<[]{}>{{}<>}}))[({{<>(
+<<<{{([[[{[{(((){})[<>[]])([{}()){()<>})}{{({}())}{{<><>}}}][<<[[]<>](<>)>{[()()]{{}()}}>[[<{}{
+<(<[{[([[(({[<{}<>>](([]{})([]()))}({<{}[]><()<>>}<[[][]]<[][]>>))<{[<()()><(){}>]([<><>]({}[]))}>)[[
+<({<<[(({{{([{{}<>}<()()>](({}{})<()<>>))((<(){}>([]{}))([<><>]))}{{<{{}{}}{<>[]}>[{(){}}<(){}>]}(
+{{{([[([[<[(<<[]{}><[]()>>(<{}>(<>{})))[([[]{}](()<>))((<><>)[{}()])]]>]<([<((<>[])(<>))[{()()}({})]>]
+{[<{((([<[({{{()[]}{()()}}((<>{})[[]<>])>){(<[[][]]>[(()())(<>[])])[<{<>[]}({}<>)>]}][(([[{}()]({}
+{<{[(({{[({[[[()()][(){}]]{<[]()>(()[])}]<(<<>()>({}{}))>})<(<<([]<>)(()())>{((){}){<>()}}>)>]{{([[[{}]]]((<<
+<<{({[{[[<[({(<>{})({}[])}<([]())[(){}]>)<<{(){}}(()<>)>{({}{})<{}<>>}>]{<[[()()]{{}<>}]({{}}<()()>)>[<
+({([{<<{[{(({(()())([][])}({{}[]}((){}))))}([{<{()[]}({}())>[({})[[]{}}]}<([<><>]([]()))>](<{(<>())(
+([<{{({<{[[{<{[]<>}>}([{[][]}[[][]]])]({[{[]<>}[[]<>]](({}[])[()()])}{({()()))<{{}[]}{[]{}}>})][[([<()
+((({<<(({(<{[<<>[]>]{[(){}]<()()>}}{<{[]}{<><>>>([<>[]]<<><>>)}>{<({(){}})[({}{})([]{})]>({{<>[]}<{}[]>}<<[
+[{<({[[([<<[(({}[])((){}))]({[[][]][[][]]})>(([{[][]}[<>()]]{{<>()}(<>)}){<{<><>}){[()[]]{{}[]}}})>])]({(
+{(<(([{{<{[[[(()[])(()<>)][{<>{}}[[][]]]]][{{<{}<>>{{}[]}}({()<>}[[]{}])}{[<{}{}>[[]<>]](<<>{}><(){}>
+[(<[<<<({{[<(({}())<()()>){[[]{}]}>({({}())([]{})}([[]()]))]{[[<{}{}><[][]>]<<{}[]>({}())>]{{{()[]}{[][]}
+([{[{<<<[{{({[{}()]}<<<>[]>{<>[]}>)((([]<>))([<>{}]))}{{[([]{})<(){}>}((()[])<[]()>)}({[(){}
+[({[<[[[(((<<[[]]<[]<>>>>{{([]<>){()[]}}})(({(<><>)({}())})<({{}[]}{[]()})[{()<>}([][])]>)
+<[[{[[{{[[[<<{()[]}<[][]>>{<<><>>[{}]}>{[<{}<>><[]<>>](((){}))}]{{<((){}){<>{}}>{(<>())[<>[]]}}<<{{}()}((
+(<[{(<<([[([[<{}{}>[<>[]]]][[{{}()}]<[<>()][()<>]>])<{[(<>{})(()[])]{[{}()][<>()]}}<((<>[]){<>()})(<()

src/day10.rs

@@ -0,0 +1,113 @@
+struct Tokenizer {
+    stack: Option<Vec<char>>,
+    corrupted: Option<char>,
+}
+
+enum Chunk {
+    Opening,
+    Closing,
+    Corrupted,
+}
+
+impl Tokenizer {
+    fn tokenize(s: &str) -> Tokenizer {
+        let mut stack = Vec::new();
+        let mut corrupted = None;
+        for c in s.chars() {
+            let top_of_stack = stack.last();
+            let token = match c {
+                '(' | '<' | '[' | '{' => Chunk::Opening,
+                ')' if top_of_stack == Some(&'(') => Chunk::Closing,
+                '>' if top_of_stack == Some(&'<') => Chunk::Closing,
+                ']' if top_of_stack == Some(&'[') => Chunk::Closing,
+                '}' if top_of_stack == Some(&'{') => Chunk::Closing,
+                ')' | '>' | ']' | '}' => Chunk::Corrupted,
+                _ => panic!("unexpected chunk {}", c),
+            };
+
+            match token {
+                Chunk::Opening => {
+                    stack.push(c);
+                }
+                Chunk::Closing => {
+                    stack.pop();
+                }
+                Chunk::Corrupted => {
+                    corrupted = Some(c);
+                    break;
+                }
+            }
+        }
+
+        match corrupted {
+            Some(_) => Tokenizer {
+                stack: None,
+                corrupted,
+            },
+            None => Tokenizer {
+                stack: Some(stack),
+                corrupted,
+            },
+        }
+    }
+
+    fn score(self) -> Option<u64> {
+        self.stack.map(|stack| {
+            stack.iter().rev().fold(0u64, |acc, c| {
+                acc * 5
+                    + match c {
+                        '(' => 1,
+                        '[' => 2,
+                        '{' => 3,
+                        '<' => 4,
+                        _ => panic!("{}", c),
+                    }
+            })
+        })
+    }
+}
+
+fn first_illegal_character(line: &str) -> Option<char> {
+    let tokenizer = Tokenizer::tokenize(line);
+    tokenizer.corrupted
+}
+
+fn completion_score(line: &str) -> Option<u64> {
+    let tokenizer = Tokenizer::tokenize(line);
+    tokenizer.score()
+}
+
+fn main() {
+    const INPUT: &str = include_str!("../inputs/day10.txt");
+
+    let score = INPUT
+        .lines()
+        .map(|line| {
+            let c = first_illegal_character(line);
+            match c {
+                Some(')') => 3,
+                Some(']') => 57,
+                Some('}') => 1197,
+                Some('>') => 25137,
+                _ => 0,
+            }
+        })
+        .sum::<u32>();
+    println!("solution {}", score);
+
+    let mut scores = INPUT
+        .lines()
+        .filter_map(completion_score)
+        .collect::<Vec<u64>>();
+    scores.sort_unstable();
+    let score = scores[(scores.len() - 1) / 2];
+    println!("solution {}", score);
+}
+
+#[test]
+fn test_completion_score() {
+    assert_eq!(completion_score("[({(<(())[]>[[{[]{<()<>>"), Some(288957));
+    assert_eq!(completion_score("[(()[<>])]({[<{<<[]>>("), Some(5566));
+    assert_eq!(completion_score("{([(<{}[<>[]}>{[]{[(<()>"), None);
+    assert_eq!(completion_score("<{([{{}}[<[[[<>{}]]]>[]]"), Some(294));
+}