Finish day11, part 2

src/days/day11.zig

@@ -1,7 +1,120 @@
 const std = @import("std");
 
-pub const title = "Day 11";
+pub const title = "Day 11: Reactor";
 
-pub fn run(_: std.mem.Allocator) !void {
+pub fn run(allocator: std.mem.Allocator) !void {
+    const input = @embedFile("./input/day11.txt");
+    //const input =
+    //    \\aaa: you hhh
+    //    \\you: bbb ccc
+    //    \\bbb: ddd eee
+    //    \\ccc: ddd eee fff
+    //    \\ddd: ggg
+    //    \\eee: out
+    //    \\fff: out
+    //    \\ggg: out
+    //    \\hhh: ccc fff iii
+    //    \\iii: out
+    //    ;
+    //const input =
+    //    \\svr: aaa bbb
+    //    \\aaa: fft
+    //    \\fft: ccc
+    //    \\bbb: tty
+    //    \\tty: ccc
+    //    \\ccc: ddd eee
+    //    \\ddd: hub
+    //    \\hub: fff
+    //    \\eee: dac
+    //    \\dac: fff
+    //    \\fff: ggg hhh
+    //    \\ggg: out
+    //    \\hhh: out
+    //    ;
+
+    var lines = std.mem.tokenizeScalar(u8, input, '\n');
+
+    var devices: std.StringHashMap([][]const u8) = .init(allocator);
+    defer {
+        var outputs_iter = devices.valueIterator();
+        while (outputs_iter.next()) |value| {
+            allocator.free(value.*);
+        }
+        devices.deinit();
+    }
+
+    while (lines.next()) |line| {
+        const device = line[0..3];
+        std.debug.print("device = {s}\n", .{device});
+
+        var outputs: std.ArrayList([]const u8) = .empty;
+        defer outputs.deinit(allocator);
+
+        var outputs_iter = std.mem.tokenizeScalar(u8, line[5..], ' ');
+        while (outputs_iter.next()) |output| {
+            try outputs.append(allocator, output);
+        }
+
+        const outputs_slice = try outputs.toOwnedSlice(allocator);
+        errdefer allocator.free(outputs_slice);
+
+        try devices.put(device, outputs_slice);
+    }
+
+    var cache: std.StringHashMap(usize) = .init(allocator);
+    defer cache.deinit();
+    try cache.ensureTotalCapacity(devices.count());
+
+    const dac_to_fft = try visitOutputs("dac", "fft", devices, &cache);
+    const svr_to_fft = try visitOutputs("svr", "fft", devices, &cache);
+    cache.clearRetainingCapacity();
+
+    const to_fft = if (dac_to_fft == 0) svr_to_fft else dac_to_fft;
+
+    const dac_start = if (dac_to_fft == 0) "fft" else "svr";
+    const end_start = if (dac_to_fft == 0) "dac" else "fft";
+
+    const to_dac = try visitOutputs(dac_start, "dac", devices, &cache);
+    cache.clearRetainingCapacity();
+
+    const to_end = try visitOutputs(end_start, "out", devices, &cache);
+
+    const result = to_fft * to_dac * to_end;
+
+    var buffer: [8]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
+
+    try stdout.print("{d}\n", .{result});
+
+    try stdout.flush();
+}
+
+fn visitOutputs(
+    start: []const u8,
+    end: []const u8,
+    devices: std.StringHashMap([][]const u8),
+    cache: *std.StringHashMap(usize),
+) !usize {
+    if (cache.get(start)) |result| {
+        return result;
+    }
+
+    var paths: usize = 0;
+    const device = devices.get(start);
+    if (device) |outputs| {
+        for (outputs) |output| {
+            if (std.mem.eql(u8, output, end)) {
+                paths += 1;
+            } else {
+                paths += try visitOutputs(output, end, devices, cache);
+            }
+        }
+        try cache.put(start, paths);
+        return paths;
+    } else {
+        std.debug.print("device {s} not found\n", .{start});
+        return 0;
+    }
 }
 

src/days/input/day11.txt

@@ -0,0 +1,609 @@
+smx: otc
+mmh: gvp
+gbo: hyf alz
+laa: vky qjq
+vrn: tbs tsr jix
+xyl: xel eur wdj
+sxm: out
+wsd: kua hpv jep
+qsj: ulu xel eur wdj
+xwa: mtd xxf hnw
+kai: ehr kaj
+uuj: you
+owb: ixr bps pim eez ejn syt qrx hxw vsy ghl gfu cgh mpk kfj
+vky: owb wlw qic
+ysd: mkp jbf btz xgg gbk tvg iju amm dws ykz azc blh xld rpr uek rcl zzy jhu
+rbc: ski xyl sdx wpw
+zmc: pal lwb rns hex
+cuu: vyo
+bqf: kmy exx ish
+jbv: ysa
+aog: ayv kwq
+fcq: qic xss owb
+hyg: out
+xoz: llx kra cqn bzn swe tdo vnz zos duw
+gnq: eya
+qmk: fcq lyd
+ggp: brz eya
+oit: yyy quh brz
+hjl: dtj lnc jps fyr
+sqg: xbz upq
+nil: diq
+xqa: jei ipw tkt
+ond: fft jko dqj pxe
+and: ahn izm esa
+cqf: xss
+rqa: ryb rwu ono fyb
+jps: byj fmv shn
+ccg: ond afk tbu
+dta: ctq jbw whr smq
+ztx: hlm ctr vgo maf fkj
+sdx: xel eur
+xwb: dds
+clh: ktb
+rtn: quh eya
+dac: nxc vug eou
+nvh: kmf yga wtv
+xgw: kep unr lju mtm
+mdx: qmk fwk fbd
+tbu: fft dqj pxe
+vil: lyz aek
+ona: zjk ovx dmv laa
+bld: zbs
+rms: vjs znm
+oku: brz yyy
+bzn: dmc fwa ykh vrn axj
+uzl: ayv fuz qhs kwq
+bhz: ggv
+kfj: xqa ucr akl
+koi: szi
+mvo: dqp kjr rbc
+rof: vgo hlm
+ixt: jws nxc vug
+ycf: out
+dmc: tsr
+nam: mvo
+rkj: quh yyy eya brz
+qxk: uty
+lwb: phc esx
+fqf: isr dax
+eou: lqz ysd
+lbb: out
+hyf: fgh wem yen taw
+dfv: nzl
+pnh: lai
+jon: eya
+guf: shn
+lmw: hlu mhq
+jff: ngn gye
+xxj: guf dtj lnc
+fbd: fcq lyd
+idw: cmg phc
+zbs: hjl
+lqz: blh ttg ykz jhu zzy uek rcl bld xgg gbk mkp amm iju tvg
+shn: goi
+hdc: wap pvr
+odf: yey ggp jtc
+rkk: zyi ubs
+fyr: fmv vtv
+pxe: ztx mmi
+ntf: dds cst aff
+lyz: gwp
+pyt: zpv ias oiz
+cqx: rod jnp
+dtj: shn vtv
+gfu: kai ctq
+ycw: ryl ixt uut dac
+yvb: jbv rms fez
+lvx: tvz vyo
+pvr: yat
+oiz: zjk ovx dmv
+biy: tdg
+xbz: cqf
+obk: jje
+jcc: ssq daa
+elu: ihl kep lju unr
+jgf: qfx bhz
+wbp: xxj cap hjl
+nne: out
+llx: axj ykh
+kso: kuk ams
+eod: nzl aap
+ryl: nxc
+epd: eou jws ats nxc vug
+wqg: uzn yyf
+qhh: lqz
+fhu: hex idw pal
+ipt: ema
+vpo: cap xxj
+thl: azd otc
+ttg: vpo
+uty: owb qic
+brz: mdl eiw gam aog nam wqg jcc kgs nac bsk zpk kul snr uzl
+faw: out
+lzw: wlw xss owb qic
+wap: iel yat qhh paa
+ffr: vnn fiv
+nug: sqg eyp sws eai dsh icy zrp mas dmf ccg hoq qze qde cqt zvl jrq gep
+ygk: jon oit
+eya: ppx nac mdl dej
+lnc: byj fmv shn
+nhq: kjv
+biq: lav xhe vcg
+hfn: pvr ydj
+leg: oii zad jje
+fft: rof taz
+maf: qic
+aap: rkj hrs svl
+axv: esa
+zou: ulu eur xel
+jtc: yyy
+pxc: gvr dyo omt
+byj: nqz goi faw
+ykh: jix tbs tsr
+fai: cst nug aff
+oty: nhq
+cek: vvv ubs zyi
+ufu: zen
+xtk: kpg tap qzv
+kil: dds aff
+ojk: lqz
+aly: qak lqz
+xxf: aff cst dds
+yua: oit ktb rwv
+vlf: ujz
+lbw: zyi uuj
+zpk: nhp urn ctg
+kuk: you ysd qak
+tmy: esa
+sqi: quh lvi
+jrq: obk leg
+yat: lqz
+atl: zpv ias oiz ona obm
+xhe: asz jbv
+gdx: oii jje
+ssq: fqf tap kpg qzv
+quh: snr kul zpk bsk nac ufu yor dej ppx aog nam wqg eiw mdl
+bvn: luk
+zny: jon ktb rwv
+jzw: aap plm
+jqp: dac
+mpk: euv llh
+fpr: gwp zmc ulq fhu
+ahn: qtl rtn
+zyi: lqz ysd
+ypn: mtd xxf
+fgh: rkk
+vgo: xss owb wlw
+axj: jix tsr
+kgv: kpg
+gfa: ona obm zpv ias
+eur: eij vil oxs xip hsd hdc gbo laz rnq lnj nuk xck twd jqp ycw btu abg koi cey hfn
+bsk: oqd hmt kew
+wrx: tas
+jix: aff nug cst dds qvv
+blc: yan
+rwv: yyy quh eya brz
+exx: blc dks
+ujz: mwp
+yyf: xya xmb fee
+icq: mtm
+hxw: viq eod
+xii: fyb
+lyb: drx mlf pkl
+puw: ona ias
+ilj: qfx xph
+wlw: gfu ghl vlf cgh mpk yfx pbj qrx hxw jsq eez syt dta ejn bps hnj pim
+icy: xbz
+wdr: gbm kil
+svl: lvi
+dax: wdj eur
+fwa: jix tsr
+fyb: you ysd qak
+whr: ehr kaj ogx nvh
+agb: mag yan
+duw: luk yzp nil
+plg: yen taw fks wem fgh
+zrp: pyt puw qyk gfa atl
+phc: you qak lqz
+aff: qze hoq qde mdx zvl jrq sqg dsh eai zrp icy mas dmf
+ulu: lnj xck twd jqp btu ycw abg koi gqf hfn eij vil oxs xip nhi hsd hdc kku laz rnq
+ezt: nug cst qvv dds
+ccu: yyy brz eya
+nuk: zpf
+ubs: ysd
+qyk: ona oiz
+kua: wlw xss qic
+ssa: kua
+uds: ier vnn fiv
+cbw: gvr
+pln: wdj ulu
+zos: htz ilj
+viq: aap nzl
+azd: jff
+esa: rtn oku
+rzd: eya brz
+syt: euv cbo
+drx: tdg
+qjq: xss owb
+jru: aat eoy dqu
+vms: bzf gkm ffr uds
+zen: vms zuv vci
+qfx: wdr
+amm: wbp vpo evr jmb zbs
+hnj: sxp viq jzw
+vtv: goi
+kep: xnp yoh evy
+evr: cap
+gvp: yyy brz lvi eya
+kxs: rod jru uvb
+daa: jlo
+fks: lbw cek
+omt: dds
+gtx: out
+jws: lqz qak
+eoy: out
+qvv: fes dmf icy zrp eai dsh iyb sqg eyp sws gep jrq mdx zvl qfd qde qze hoq ccg
+smq: kaj
+kmy: agb
+qde: atl
+fez: znm mvj vjs
+cey: wrx ryw lbx
+ema: brz eya lvi quh yyy
+zfg: cst nug aff qvv
+pim: yip pxl ujz
+zge: lzw
+ykz: yrg bss smx
+yyy: snr zpk uzl ufu bsk dej yte kgs gam eiw wqg
+yor: kew
+cmg: lqz qak ysd
+xya: zou pln uaz
+zpv: laa
+yen: cek rkk fce iwk
+boc: eay hlu
+ygu: xya ofj
+xnp: oic zfg eft xwb
+nlb: izm
+fmv: nqz
+mag: aem wtx qrc pyc ipu
+tdo: jgf
+znm: sxm lbb
+mtm: xnp
+khk: ipt qvi
+vyo: eur wdj
+kye: out
+uvb: dqu aat yvz
+xck: lyz fpr aek arq
+acb: wtv gts
+gep: qxk upq
+ihl: xnp yoh
+eyp: qyk
+lai: qsj
+ipu: out
+isr: ulu
+qrc: out
+jhu: bqf
+eij: uut dac ryl epd
+tvg: yrg thl mvu bss
+pbj: ucr
+cst: ccg sws hoq qze dsh qde cqt
+yzp: xwa diq cft ypn
+uut: eou ats
+fee: zou
+dqj: mmi taz rof ztx
+rnq: arq aek
+yfk: yvb zzh
+lvi: jcc dej mdl gam aog nam zpk kul uzl ufu bsk nac
+tap: sxw
+jsq: dfv sxp viq jzw
+tdg: aff nug cst dds
+cgh: tmy oze nlb and
+qzv: dax
+jtn: xhe
+kjr: ski wpw sdx xyl
+ski: wdj xel
+oqd: zuv
+ppx: zen hmt kew
+vcg: jbv
+jbw: nvh
+ctg: dqp
+dcv: owb wlw qic
+kzs: rxd lai cuu lvx
+dws: bss yrg thl mvu
+ara: dds qvv cst nug aff
+ctr: owb wlw
+ctq: ehr kaj acb
+zpf: fgh fks
+pyc: out
+ras: gvr omt
+iby: xxb rqa vlx
+gam: mah ygu uzn
+ulq: idw lwb pal
+gkm: ier
+cqn: pdv elu
+tvz: ulu
+obm: laa
+btu: alz
+wtx: out
+xel: oty oxs vil eij hsd nhi hdc gbo kku lnj ycw btu jqp xck gqf hfn cey koi abg
+uxa: lwb hex rns
+yga: gnq
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+mvu: otc exw
+yrg: otc azd
+kul: qsu xtk ssq daa kgv
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+xhy: wus khk mwp
+ehr: wtv gts yga
+fes: zge
+rwu: you qak ysd lqz
+hnw: cst
+goi: out
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+hzh: wlw xss qic
+lbs: vlx rqa
+dds: mdx zvl qde qfd qze jrq zrp icy iyb dsh eyp sqg fes dmf mas
+tsh: hpv kua
+svr: xoz lak pif ryf dyv
+gua: hlu
+jei: jtc ggp
+wpw: xel eur wdj ulu
+jbf: biq jtn hut ppv yfk
+hoq: qmk fwk cxr fbd
+blh: evr vpo zbs jmb
+mas: gdx
+afk: jko pxe
+zzy: lmw boc
+vsy: tmy oze axv and
+htz: xph qfx bhz
+yte: mah ygu uzn rcr
+zuv: bzf gkm ffr uds
+yvz: out
+ejn: dok llh euv
+jlo: dax isr
+qvi: gvp ema rzd
+mdl: mah
+wdj: hfn gqf cey koi jqp twd lnj rnq gbo kku hdc hsd oty vil eij abg ycw btu xck nuk nhi oxs
+ias: dmv zjk ovx
+laz: nhq
+ish: blc
+pkl: ezt ara
+xhj: elu
+tlp: ais
+mux: zrm uvb
+vci: bzf gkm uds
+nie: wtx aem qrc
+ike: wdj xel ulu
+abg: pvr wap
+ono: lqz
+yip: khk
+oze: ahn izm
+lak: bvn mbd llx xhj lyb pxo
+dmf: obk leg
+wus: ipt qvi
+oic: nug cst qvv dds
+rpr: ifc fjg mfu
+vvv: qak
+qtl: lvi brz quh yyy
+rqt: pdv icq
+yoh: eft ntf oic
+aby: nug dds
+yfx: axv tmy
+xmb: uaz pln
+hrs: brz quh yyy
+eez: llh cbo
+lyd: qic owb xss wlw
+dyo: dds qvv aff cst nug
+evy: xwb eft ntf
+plv: esz ktb jon
+luk: xwa ypn
+nqz: out
+ier: wdj eur ulu
+yey: quh eya lvi brz
+otc: svv tlp jff
+qze: leg gdx obk
+aek: gwp ulq
+mah: xmb fee xya
+pxl: khk xux wus
+wem: iwk cek lbw rkk
+nhi: uut ryl epd
+cui: out
+qak: ykz xmj jbf rpr xgg blh
+qwm: eya lvi brz quh
+dsh: zge qxk upq xbz
+hmt: zuv
+bss: azd otc
+rxd: vyo qsj
+eay: uhs mux kxs
+vnn: ulu wdj eur xel
+iju: ckk lmw gua
+fiv: wdj eur xel ulu
+izm: rtn oku
+xld: fjg mfu ifc
+xph: ggv nqb
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+gqf: zpf amk plg hyf
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+hlu: mux cqx
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+ypw: jgf
+pdv: kep
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+fya: llv iby lbs
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+gye: kye gme
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+fwk: lyd
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+nsp: brz eya yyy
+xss: vsy bps ixr hxw syt pbj kfj gfu
+nac: kgv xtk qsu
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+svv: ais gye
+mtd: cst dds qvv
+ixr: and nlb axv
+jdf: pxc cbw
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+jep: wlw xss
+nqb: lvh
+zrm: yvz eoy aat cui
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+ayv: srk pnh ija kzs
+gme: out
+oxs: szi nhq kso
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+xlu: luk
+aem: out
+mlf: ara
+kwq: srk pnh kzs
+jmb: xxj cap
+dqu: out
+iel: ysd
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+nhp: dqp kjr
+ifc: ish
+llv: rqa xii xxb
+dea: luk yzp nil
+ngn: nne gme ycf hyg
+ryf: xlu rqt swe bvn lyb duw cqn bzn jdf wnr wee ypw pxo vnz xhj zos
+lef: brz quh
+mbd: pxc
+cap: dtj guf
+rcl: wbp evr vpo jmb
+zvl: fbd cxr fwk
+btz: lmw gua
+ktb: brz yyy
+taz: ctr hlm vgo fkj
+mkp: jtn hut yfk ppv
+iyb: afk tbu
+gbm: nug dds
+swe: ras
+ckk: hlu eay
+rni: out
+bzf: fiv
+qhs: ija
+rod: yvz
+amk: yen taw
+vjs: rni sxm
+hlm: owb xss
+zjk: oiw
+mvj: gtx rni
+ryw: iby llv
+npf: quh brz lvi
+zad: ssa tsh
+esx: lqz ysd
+mwp: mmh
+alz: wem yen
+kra: luk nil
+xmj: smx
+dej: kew