From 8905c1db37bb1698430ce3d25ff89cc9487dce91 Mon Sep 17 00:00:00 2001
From: Jasper Bok <hello@jasperbok.nl>
Date: Fri, 16 Dec 2022 19:34:27 +0100
Subject: [PATCH] Add solution for day 7

---
 day7/input.txt     | 1013 ++++++++++++++++++++++++++++++++++++++++++++
 day7/part1.py      |  139 ++++++
 day7/part2.py      |   64 +++
 day7/testinput.txt |   23 +
 day7/utils.py      |   90 ++++
 5 files changed, 1329 insertions(+)
 create mode 100644 day7/input.txt
 create mode 100644 day7/part1.py
 create mode 100644 day7/part2.py
 create mode 100644 day7/testinput.txt
 create mode 100644 day7/utils.py

diff --git a/day7/input.txt b/day7/input.txt
new file mode 100644
index 0000000..c988c21
--- /dev/null
+++ b/day7/input.txt
@@ -0,0 +1,1013 @@
+$ cd /
+$ ls
+dir jmtrrrp
+dir jssnn
+dir lbrmb
+11968 pcccp
+$ cd jmtrrrp
+$ ls
+77968 chq.jvb
+dir fmgsql
+$ cd fmgsql
+$ ls
+dir dbnsfp
+dir vvp
+$ cd dbnsfp
+$ ls
+51021 crlq.lrj
+186829 dhcrzvbr.wmn
+16232 fvhn.fqm
+54150 qpbqqj.rpg
+$ cd ..
+$ cd vvp
+$ ls
+179105 rrcsndz.tzp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jssnn
+$ ls
+dir bphfqs
+dir dbnsfp
+dir pcccp
+dir snr
+dir zjbvwsnv
+$ cd bphfqs
+$ ls
+110077 dhcrzvbr.wmn
+$ cd ..
+$ cd dbnsfp
+$ ls
+dir hgvh
+dir jtqdcmsz
+154197 rrcsndz.tzp
+$ cd hgvh
+$ ls
+dir qjnbg
+$ cd qjnbg
+$ ls
+dir bqzfpr
+$ cd bqzfpr
+$ ls
+124394 wjsbsp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jtqdcmsz
+$ ls
+275597 dbnsfp.fpg
+$ cd ..
+$ cd ..
+$ cd pcccp
+$ ls
+dir cnbd
+85621 cqzvwl
+dir dbnsfp
+114355 hbhp.cfv
+dir mcgq
+dir pcccp
+dir qpbqqj
+224038 rrcsndz.tzp
+dir zcsm
+27570 zjbvwsnv.fjt
+$ cd cnbd
+$ ls
+dir jrbz
+dir pphv
+$ cd jrbz
+$ ls
+dir dwvlwfq
+$ cd dwvlwfq
+$ ls
+32237 fwclr.rnb
+$ cd ..
+$ cd ..
+$ cd pphv
+$ ls
+180370 dhcrzvbr.wmn
+50154 dzvwdwl.gbt
+123965 mlsv.hlw
+163116 wnhtwr.mwl
+$ cd ..
+$ cd ..
+$ cd dbnsfp
+$ ls
+252181 btv.mpv
+dir hwncj
+dir pcccp
+$ cd hwncj
+$ ls
+51410 jbd.fcm
+$ cd ..
+$ cd pcccp
+$ ls
+258123 chq.jvb
+$ cd ..
+$ cd ..
+$ cd mcgq
+$ ls
+206506 qpbqqj.bbb
+$ cd ..
+$ cd pcccp
+$ ls
+193219 ddhtnql.hmb
+134114 hjbpzqzb.rwn
+108927 lznndn.nqd
+73241 ncdrv
+$ cd ..
+$ cd qpbqqj
+$ ls
+dir crdt
+dir tgchdnc
+$ cd crdt
+$ ls
+205710 chq.jvb
+$ cd ..
+$ cd tgchdnc
+$ ls
+dir bdw
+dir dpl
+dir jssnn
+dir pcccp
+dir plpzbm
+$ cd bdw
+$ ls
+211300 dbnsfp.tjm
+$ cd ..
+$ cd dpl
+$ ls
+287744 rsbjqwm
+$ cd ..
+$ cd jssnn
+$ ls
+dir jssnn
+$ cd jssnn
+$ ls
+9644 hmjhshg.vbv
+$ cd ..
+$ cd ..
+$ cd pcccp
+$ ls
+dir jssnn
+85888 pcccp.hdj
+dir qpbqqj
+dir rmscmwtv
+$ cd jssnn
+$ ls
+129698 crlq.lrj
+7499 dhcrzvbr.wmn
+283607 qpbqqj.djr
+234874 wqnrhll
+$ cd ..
+$ cd qpbqqj
+$ ls
+184229 qqpb.ftd
+$ cd ..
+$ cd rmscmwtv
+$ ls
+188048 dhcrzvbr.wmn
+dir jwtpgbnt
+$ cd jwtpgbnt
+$ ls
+209946 hgg
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd plpzbm
+$ ls
+32627 tlb.qmc
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zcsm
+$ ls
+dir lczflft
+dir zjbvwsnv
+dir zmh
+$ cd lczflft
+$ ls
+40043 dzgnvlw.scr
+dir lrnb
+$ cd lrnb
+$ ls
+109881 bjpbs
+dir jssnn
+46901 npmw
+$ cd jssnn
+$ ls
+9216 sgrp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+214676 jssnn.hgn
+$ cd ..
+$ cd zmh
+$ ls
+dir jdt
+dir rggpltr
+$ cd jdt
+$ ls
+147387 jhhsv
+90052 jssnn.wns
+53105 qpbqqj.dzq
+$ cd ..
+$ cd rggpltr
+$ ls
+121454 dbnsfp.dzt
+dir gcc
+$ cd gcc
+$ ls
+dir zbqwl
+dir zjbvwsnv
+$ cd zbqwl
+$ ls
+260297 pcccp.jrw
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+248709 pcccp.tph
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd snr
+$ ls
+152569 chq.jvb
+1437 crlq.lrj
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+dir cqhb
+53235 ghhtl.bhv
+199640 npcfdw
+136346 qpbqqj.lmv
+dir zjbvwsnv
+$ cd cqhb
+$ ls
+24712 sqqf
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+dir gzqg
+dir hfbfvn
+dir srsphr
+dir vgvdcvc
+$ cd gzqg
+$ ls
+dir jjw
+$ cd jjw
+$ ls
+240052 zdcjjz.pmg
+$ cd ..
+$ cd ..
+$ cd hfbfvn
+$ ls
+278190 bfgndw.pvf
+$ cd ..
+$ cd srsphr
+$ ls
+42591 zjbvwsnv.hgh
+$ cd ..
+$ cd vgvdcvc
+$ ls
+120322 rrcsndz.tzp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd lbrmb
+$ ls
+dir bjhpdj
+42241 crlq.lrj
+dir dbnsfp
+244610 dhcrzvbr.wmn
+dir hppb
+dir mcnzs
+dir npntsr
+13625 tpjpcsgp.dlz
+219424 vvpbt.zvf
+dir zjbvwsnv
+191467 zjbvwsnv.htn
+$ cd bjhpdj
+$ ls
+dir bqjvst
+204722 dbnsfp
+dir dhltrqqq
+226082 dmdqcjp
+dir fcqwgzp
+dir jssnn
+6453 jssnn.ndh
+23799 jssnn.zqn
+dir nwglfhpl
+dir pcccp
+dir pdnj
+269246 shzqns.nws
+dir sjstqlcb
+dir zssln
+$ cd bqjvst
+$ ls
+202793 dbnsfp.pjj
+259783 jssnn
+dir rbvbhnvs
+30683 rvddnjmb.tlz
+dir tzhslnv
+$ cd rbvbhnvs
+$ ls
+86934 vrtrf.htt
+$ cd ..
+$ cd tzhslnv
+$ ls
+76278 mghcwdlr.tsc
+$ cd ..
+$ cd ..
+$ cd dhltrqqq
+$ ls
+dir mfd
+dir pcccp
+dir smmb
+251164 wsdnsgtt.lhr
+191876 zvr.bbz
+$ cd mfd
+$ ls
+51017 crlq.lrj
+99213 rjtbnnnq.hgd
+$ cd ..
+$ cd pcccp
+$ ls
+160487 dhcrzvbr.wmn
+dir nhdrnthj
+dir qpbqqj
+$ cd nhdrnthj
+$ ls
+181291 bbn.wtm
+186551 fnw.tnn
+23622 rrcsndz.tzp
+dir zjbvwsnv
+$ cd zjbvwsnv
+$ ls
+227547 dhcrzvbr.wmn
+$ cd ..
+$ cd ..
+$ cd qpbqqj
+$ ls
+212353 crlq.lrj
+170195 dhcrzvbr.wmn
+dir ttvp
+$ cd ttvp
+$ ls
+185994 tgjcfgjv
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd smmb
+$ ls
+dir dbnsfp
+85354 dbnsfp.zpn
+80665 dfmmjbm.rnr
+135989 dhcrzvbr.wmn
+93718 lrbzr.nfs
+dir mjpfnfns
+dir nsdpfnhb
+dir pmnssvd
+32270 qpbqqj.vtd
+$ cd dbnsfp
+$ ls
+31796 gzs.rgv
+64506 vbjncw.bpz
+181659 vjlfrdp.tqh
+$ cd ..
+$ cd mjpfnfns
+$ ls
+231611 chq.jvb
+17518 cmnlrzq.hvh
+144795 dbnsfp
+162194 jssnn.wjz
+29305 vdqnlw.fzf
+$ cd ..
+$ cd nsdpfnhb
+$ ls
+281844 chq.jvb
+$ cd ..
+$ cd pmnssvd
+$ ls
+165816 dfvl.czb
+144561 gbn
+150785 lnzdwrmb
+111214 rrcsndz.tzp
+164156 tzgdb.hht
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd fcqwgzp
+$ ls
+199161 dhcrzvbr.wmn
+34251 rrcsndz.tzp
+198345 vjlfrdp.tqh
+167001 zjbvwsnv.bsd
+$ cd ..
+$ cd jssnn
+$ ls
+dir ccblfvl
+103180 dhcrzvbr.wmn
+dir prw
+dir tzqfn
+dir zjbvwsnv
+166467 zjbvwsnv.tdt
+$ cd ccblfvl
+$ ls
+159752 crlq.lrj
+20805 jssnn.dvb
+243040 lct.zll
+27492 qbh
+27174 vjlfrdp.tqh
+dir zvfwq
+$ cd zvfwq
+$ ls
+135126 chq.jvb
+41664 gphw.vzd
+dir hmrdghbr
+dir jssnn
+dir qzzb
+dir tmdlcv
+$ cd hmrdghbr
+$ ls
+dir jvgpwrbs
+$ cd jvgpwrbs
+$ ls
+dir wzdv
+$ cd wzdv
+$ ls
+26834 qpbqqj.njf
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jssnn
+$ ls
+90199 jqqmqddf.qnz
+$ cd ..
+$ cd qzzb
+$ ls
+dir mgpql
+dir src
+dir zvdgc
+$ cd mgpql
+$ ls
+141852 qpbqqj
+$ cd ..
+$ cd src
+$ ls
+204425 lqmcbndm.jrj
+75571 qsbrsv.jcm
+$ cd ..
+$ cd zvdgc
+$ ls
+268742 ffjmrmmz.lhg
+18385 rvmp.hjv
+$ cd ..
+$ cd ..
+$ cd tmdlcv
+$ ls
+182587 sfwvjrj.mzl
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd prw
+$ ls
+207429 dbnsfp.rqf
+dir ptgn
+dir pzgpqp
+252902 rbt
+169694 trg.rsh
+$ cd ptgn
+$ ls
+dir jssnn
+dir qpbqqj
+dir rpd
+$ cd jssnn
+$ ls
+189316 dbnsfp.bqc
+$ cd ..
+$ cd qpbqqj
+$ ls
+167937 zjbvwsnv.bhz
+$ cd ..
+$ cd rpd
+$ ls
+8775 crlq.lrj
+$ cd ..
+$ cd ..
+$ cd pzgpqp
+$ ls
+dir pcccp
+$ cd pcccp
+$ ls
+51496 pcccp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd tzqfn
+$ ls
+dir cbpfvdp
+285700 crlq.lrj
+7426 dbnsfp.fsd
+dir gdl
+141367 jssnn.hmw
+184482 sczphnp.vnc
+126288 vjlfrdp.tqh
+dir wndpdj
+$ cd cbpfvdp
+$ ls
+dir cvfr
+dir qpbqqj
+$ cd cvfr
+$ ls
+dir jfrnvts
+dir qpbqqj
+$ cd jfrnvts
+$ ls
+dir vwdn
+$ cd vwdn
+$ ls
+236936 vjlfrdp.tqh
+$ cd ..
+$ cd ..
+$ cd qpbqqj
+$ ls
+254275 bqd
+$ cd ..
+$ cd ..
+$ cd qpbqqj
+$ ls
+dir jssnn
+201960 qpbqqj
+$ cd jssnn
+$ ls
+131127 jssnn
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd gdl
+$ ls
+225146 hsgzmtp.wcs
+204436 jssnn.lhh
+64007 mjzjgfg.jsb
+$ cd ..
+$ cd wndpdj
+$ ls
+245412 bvcq
+211386 dbnsfp.tqd
+186962 fql.mww
+dir hlmhtfz
+117446 smvjvcn.lcp
+$ cd hlmhtfz
+$ ls
+150152 lrdhbq.rvm
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+179703 fvmbz
+87552 qtz.ccw
+129764 rrcsndz.tzp
+$ cd ..
+$ cd ..
+$ cd nwglfhpl
+$ ls
+66039 crlq.lrj
+dir cwq
+dir dlgrsw
+267814 frhlttn.nmd
+dir hmprt
+dir qpbqqj
+dir wnfzznfh
+$ cd cwq
+$ ls
+77655 cpjnwzh
+dir pcccp
+dir zjbvwsnv
+dir zzhjfmnr
+$ cd pcccp
+$ ls
+dir pcccp
+$ cd pcccp
+$ ls
+245309 bggzbrg.flf
+$ cd ..
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+196915 gnmfb.dzq
+dir ngqbdqp
+$ cd ngqbdqp
+$ ls
+355 rrcsndz.tzp
+$ cd ..
+$ cd ..
+$ cd zzhjfmnr
+$ ls
+dir dbnsfp
+$ cd dbnsfp
+$ ls
+223184 chq.jvb
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd dlgrsw
+$ ls
+181906 chq.jvb
+5636 dbnsfp
+219889 jbr.slc
+dir zrntbl
+$ cd zrntbl
+$ ls
+61864 brnpgpwt
+138980 qpbqqj
+$ cd ..
+$ cd ..
+$ cd hmprt
+$ ls
+90249 dbnsfp.mbd
+$ cd ..
+$ cd qpbqqj
+$ ls
+290377 crlq.lrj
+$ cd ..
+$ cd wnfzznfh
+$ ls
+83022 hclmps
+64095 zhm
+$ cd ..
+$ cd ..
+$ cd pcccp
+$ ls
+dir rdzntr
+dir rvccq
+$ cd rdzntr
+$ ls
+239028 rrcsndz.tzp
+$ cd ..
+$ cd rvccq
+$ ls
+22746 chq.jvb
+288752 jjvppq.swt
+dir msgwsnjq
+dir pggz
+228469 vjlfrdp.tqh
+$ cd msgwsnjq
+$ ls
+102522 lwgqc.mhv
+25239 ndm.llf
+$ cd ..
+$ cd pggz
+$ ls
+dir cnjqsqj
+$ cd cnjqsqj
+$ ls
+229407 shpnq
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd pdnj
+$ ls
+193069 rwnhgttz.pvp
+$ cd ..
+$ cd sjstqlcb
+$ ls
+263295 chq.jvb
+224091 jss.wtr
+$ cd ..
+$ cd zssln
+$ ls
+5859 ncdlcr.dll
+$ cd ..
+$ cd ..
+$ cd dbnsfp
+$ ls
+271252 dhcrzvbr.wmn
+$ cd ..
+$ cd hppb
+$ ls
+259968 jssnn
+81292 qpqqb.clj
+$ cd ..
+$ cd mcnzs
+$ ls
+170903 crlq.lrj
+59482 dhcrzvbr.wmn
+dir dqzwzbgm
+dir gnrztn
+286736 jssnn.jcm
+32791 phqsgl
+dir pzjnrwt
+197323 vjlfrdp.tqh
+dir wvnwbpct
+$ cd dqzwzbgm
+$ ls
+78575 qpbqqj
+251546 qpbqqj.slb
+$ cd ..
+$ cd gnrztn
+$ ls
+158603 hdnwmd.rhj
+dir nbfdtwzr
+178239 ptnchzpg
+40517 rrcsndz.tzp
+dir smvb
+198007 vjlfrdp.tqh
+$ cd nbfdtwzr
+$ ls
+200354 crlq.lrj
+$ cd ..
+$ cd smvb
+$ ls
+163921 zjbvwsnv.brz
+$ cd ..
+$ cd ..
+$ cd pzjnrwt
+$ ls
+33891 lwrll
+259646 pcccp.sfn
+106835 pqfzthjq
+189673 rrcsndz.tzp
+$ cd ..
+$ cd wvnwbpct
+$ ls
+234188 dhcrzvbr.wmn
+dir gmtpsgv
+86379 jssnn
+146663 sfpmdbbd.jvt
+25795 vjlfrdp.tqh
+$ cd gmtpsgv
+$ ls
+18642 chq.jvb
+3046 cznlwtw
+26335 ddgpngrc
+116455 vnnls.hsg
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd npntsr
+$ ls
+dir cccjdcvb
+206657 chq.jvb
+280518 crlq.lrj
+dir dbnsfp
+dir jphnn
+dir jssnn
+dir mpl
+195193 rrcsndz.tzp
+dir rztc
+dir znwp
+$ cd cccjdcvb
+$ ls
+192965 mcr.sfq
+$ cd ..
+$ cd dbnsfp
+$ ls
+dir gfns
+173317 jssnn.tjq
+dir mgr
+68817 mvwcwfcr.zmz
+dir pqfht
+108571 swfl.dtj
+10398 tvvvv
+dir vzg
+174361 zjbvwsnv
+$ cd gfns
+$ ls
+203999 zjbvwsnv.hfg
+$ cd ..
+$ cd mgr
+$ ls
+dir zjbvwsnv
+$ cd zjbvwsnv
+$ ls
+26871 tqlgcf.jrn
+$ cd ..
+$ cd ..
+$ cd pqfht
+$ ls
+199590 clpvscl.rlm
+dir dwlhv
+dir vhzfzhrb
+$ cd dwlhv
+$ ls
+130761 qpbqqj
+242752 rrcsndz.tzp
+$ cd ..
+$ cd vhzfzhrb
+$ ls
+dir njdgcbvm
+$ cd njdgcbvm
+$ ls
+dir snjfqg
+$ cd snjfqg
+$ ls
+dir qpwh
+$ cd qpwh
+$ ls
+153353 qsjpj
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd vzg
+$ ls
+dir pcccp
+$ cd pcccp
+$ ls
+dir jfbtl
+$ cd jfbtl
+$ ls
+209199 dbnsfp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jphnn
+$ ls
+52305 crlq.lrj
+193480 gmms.whz
+59354 nmq.dww
+64638 qpbqqj
+47072 rrcsndz.tzp
+$ cd ..
+$ cd jssnn
+$ ls
+69168 crlq.lrj
+1549 dhcrzvbr.wmn
+219596 hdmczg.lmm
+108063 jssnn
+24327 vjlfrdp.tqh
+dir zjbvwsnv
+$ cd zjbvwsnv
+$ ls
+189952 chq.jvb
+$ cd ..
+$ cd ..
+$ cd mpl
+$ ls
+144856 bqrrzm
+249487 crlq.lrj
+dir ffqgpgfg
+93632 flqwtn.nsz
+dir mwpcqr
+195910 pdqwn.lcg
+$ cd ffqgpgfg
+$ ls
+66459 dbnsfp
+200500 lcmt.zmz
+207093 qpbqqj
+77042 vjlfrdp.tqh
+57109 wwzv.hbn
+$ cd ..
+$ cd mwpcqr
+$ ls
+dir zjbvwsnv
+$ cd zjbvwsnv
+$ ls
+166393 vjlfrdp.tqh
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd rztc
+$ ls
+57788 chq.jvb
+$ cd ..
+$ cd znwp
+$ ls
+164627 chq.jvb
+$ cd ..
+$ cd ..
+$ cd zjbvwsnv
+$ ls
+dir dgrrl
+71529 jssnn
+198617 pcccp.qqh
+dir phggn
+56842 zjbvwsnv.vqd
+$ cd dgrrl
+$ ls
+dir czm
+dir fhhlbdlz
+dir gstjw
+dir qpbqqj
+dir stgb
+$ cd czm
+$ ls
+dir jssnn
+$ cd jssnn
+$ ls
+162335 chq.jvb
+30099 mfdgdw
+96389 pcdsd.wmw
+251423 tmz.lcb
+205979 vpltdt.gtv
+$ cd ..
+$ cd ..
+$ cd fhhlbdlz
+$ ls
+dir qpbqqj
+dir vdjs
+dir zgz
+$ cd qpbqqj
+$ ls
+285561 chq.jvb
+263924 lbqcfdrs
+138854 pcccp.dtn
+$ cd ..
+$ cd vdjs
+$ ls
+32688 chq.jvb
+223233 tbn.blt
+$ cd ..
+$ cd zgz
+$ ls
+92804 bqltmv.wzb
+$ cd ..
+$ cd ..
+$ cd gstjw
+$ ls
+151784 fvfszzzn.cbh
+$ cd ..
+$ cd qpbqqj
+$ ls
+dir blztqf
+dir plgnh
+$ cd blztqf
+$ ls
+195097 wlvmtz
+$ cd ..
+$ cd plgnh
+$ ls
+dir dbnsfp
+246221 dhcrzvbr.wmn
+271121 jhwmmzls.mhw
+170162 pcccp.dpp
+37872 qpbqqj
+$ cd dbnsfp
+$ ls
+dir dhpnr
+$ cd dhpnr
+$ ls
+152837 pcccp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd stgb
+$ ls
+248436 vjlfrdp.tqh
+$ cd ..
+$ cd ..
+$ cd phggn
+$ ls
+284602 dhcrzvbr.wmn
+dir lctr
+dir rjmc
+66651 rrcsndz.tzp
+117525 vth.fgw
+156877 wcqnjzbq.dgf
+7803 zpsrzclh.bzw
+$ cd lctr
+$ ls
+212339 jssnn.whp
+dir jzhcqb
+99974 pcccp.zhs
+111354 pmc
+104899 vjlfrdp.tqh
+93496 zhwmbw
+$ cd jzhcqb
+$ ls
+dir zjbvwsnv
+$ cd zjbvwsnv
+$ ls
+146807 rbrg
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd rjmc
+$ ls
+dir fvbmsc
+139747 glwmr.lrg
+dir gvnnz
+102023 tbj.qmz
+dir vsztsjfh
+$ cd fvbmsc
+$ ls
+136838 vpvbz.qtw
+$ cd ..
+$ cd gvnnz
+$ ls
+95498 zjbvwsnv
+$ cd ..
+$ cd vsztsjfh
+$ ls
+215479 ffwlcrwb
diff --git a/day7/part1.py b/day7/part1.py
new file mode 100644
index 0000000..6200421
--- /dev/null
+++ b/day7/part1.py
@@ -0,0 +1,139 @@
+"""
+--- Day 7: No Space Left On Device ---
+
+You can hear birds chirping and raindrops hitting leaves as the
+expedition proceeds. Occasionally, you can even hear much louder sounds
+in the distance; how big do the animals get out here, anyway?
+
+The device the Elves gave you has problems with more than just its
+communication system. You try to run a system update:
+
+$ system-update --please --pretty-please-with-sugar-on-top
+Error: No space left on device
+Perhaps you can delete some files to make space for the update?
+
+You browse around the filesystem to assess the situation and save the
+resulting terminal output (your puzzle input). For example:
+
+    $ cd /
+    $ ls
+    dir a
+    14848514 b.txt
+    8504156 c.dat
+    dir d
+    $ cd a
+    $ ls
+    dir e
+    29116 f
+    2557 g
+    62596 h.lst
+    $ cd e
+    $ ls
+    584 i
+    $ cd ..
+    $ cd ..
+    $ cd d
+    $ ls
+    4060174 j
+    8033020 d.log
+    5626152 d.ext
+    7214296 k
+
+The filesystem consists of a tree of files (plain data) and directories
+(which can contain other directories or files). The outermost directory
+is called /. You can navigate around the filesystem, moving into or out
+of directories and listing the contents of the directory you're
+currently in.
+
+Within the terminal output, lines that begin with $ are commands you
+executed, very much like some modern computers:
+
+- cd means change directory. This changes which directory is the current
+  directory, but the specific result depends on the argument:
+  - cd x moves in one level: it looks in the current directory for the
+    directory named x and makes it the current directory.
+  - cd .. moves out one level: it finds the directory that contains the
+    current directory, then makes that directory the current directory.
+  - cd / switches the current directory to the outermost directory, /.
+- ls means list. It prints out all of the files and directories
+  immediately contained by the current directory:
+  - 123 abc means that the current directory contains a file named abc
+    with size 123.
+  - dir xyz means that the current directory contains a directory named
+    xyz.
+
+Given the commands and output in the example above, you can determine
+that the filesystem looks visually like this:
+
+- / (dir)
+  - a (dir)
+    - e (dir)
+      - i (file, size=584)
+    - f (file, size=29116)
+    - g (file, size=2557)
+    - h.lst (file, size=62596)
+  - b.txt (file, size=14848514)
+  - c.dat (file, size=8504156)
+  - d (dir)
+    - j (file, size=4060174)
+    - d.log (file, size=8033020)
+    - d.ext (file, size=5626152)
+    - k (file, size=7214296)
+
+Here, there are four directories: / (the outermost directory), a and d
+(which are in /), and e (which is in a). These directories also contain
+files of various sizes.
+
+Since the disk is full, your first step should probably be to find
+directories that are good candidates for deletion. To do this, you need
+to determine the total size of each directory. The total size of a
+directory is the sum of the sizes of the files it contains, directly or
+indirectly. (Directories themselves do not count as having any intrinsic
+size.)
+
+The total sizes of the directories above can be found as follows:
+
+- The total size of directory e is 584 because it contains a single file
+  i of size 584 and no other directories.
+- The directory a has total size 94853 because it contains files f (size
+  29116), g (size 2557), and h.lst (size 62596), plus file i indirectly
+  (a contains e which contains i).
+- Directory d has total size 24933642.
+- As the outermost directory, / contains every file. Its total size is
+  48381165, the sum of the size of every file.
+
+To begin, find all of the directories with a total size of at most
+100000, then calculate the sum of their total sizes. In the example
+above, these directories are a and e; the sum of their total sizes is
+95437 (94853 + 584). (As in this example, this process can count files
+more than once!)
+
+Find all of the directories with a total size of at most 100000. What
+is the sum of the total sizes of those directories?
+"""
+from utils import Dir, parse_commands_to_tree, print_tree
+
+
+def main():
+    with open("input.txt", "r", encoding="utf-8") as input_file:
+        tree = parse_commands_to_tree(input_file.read().split("\n"))
+
+    print_tree(tree)
+
+    def find_large_dirs(directory):
+        total_size = 0
+
+        for thing in directory.contents:
+            if isinstance(thing, Dir):
+                if thing.size < 100000:
+                    total_size += thing.size
+                total_size += find_large_dirs(thing)
+
+        return total_size
+
+    total_size = find_large_dirs(tree)
+    print(f"Total size: {total_size}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/day7/part2.py b/day7/part2.py
new file mode 100644
index 0000000..cbd229d
--- /dev/null
+++ b/day7/part2.py
@@ -0,0 +1,64 @@
+"""
+--- Part Two ---
+
+Now, you're ready to choose a directory to delete.
+
+The total disk space available to the filesystem is 70000000. To run the
+update, you need unused space of at least 30000000. You need to find a
+directory you can delete that will free up enough space to run the
+update.
+
+In the example above, the total size of the outermost directory (and
+thus the total amount of used space) is 48381165; this means that the
+size of the unused space must currently be 21618835, which isn't quite
+the 30000000 required by the update. Therefore, the update still
+requires a directory with total size of at least 8381165 to be deleted
+before it can run.
+
+To achieve this, you have the following options:
+
+- Delete directory e, which would increase unused space by 584.
+- Delete directory a, which would increase unused space by 94853.
+- Delete directory d, which would increase unused space by 24933642.
+- Delete directory /, which would increase unused space by 48381165.
+
+Directories e and a are both too small; deleting them would not free up
+enough space. However, directories d and / are both big enough! Between
+these, choose the smallest: d, increasing unused space by 24933642.
+
+Find the smallest directory that, if deleted, would free up enough space
+on the filesystem to run the update. What is the total size of that
+directory?
+"""
+from utils import Dir, parse_commands_to_tree, print_tree
+
+
+DISK_SIZE = 70000000
+REQUIRED_SPACE = 30000000
+
+
+def main():
+    with open("input.txt", "r", encoding="utf-8") as input_file:
+        tree = parse_commands_to_tree(input_file.read().split("\n"))
+
+    used_disk_space = tree.size
+    additional_required_space = REQUIRED_SPACE - (DISK_SIZE - used_disk_space)
+
+    def find_candidates(directory):
+        candidates = []
+
+        for thing in directory.contents:
+            if isinstance(thing, Dir):
+                if thing.size >= additional_required_space:
+                    candidates.append(thing)
+                candidates.extend(find_candidates(thing))
+
+        return candidates
+
+    candidates = find_candidates(tree)
+    smallest_size = min([candidate.size for candidate in candidates])
+    print(f"The smallest size is {smallest_size}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/day7/testinput.txt b/day7/testinput.txt
new file mode 100644
index 0000000..09a921e
--- /dev/null
+++ b/day7/testinput.txt
@@ -0,0 +1,23 @@
+$ cd /
+$ ls
+dir a
+14848514 b.txt
+8504156 c.dat
+dir d
+$ cd a
+$ ls
+dir e
+29116 f
+2557 g
+62596 h.lst
+$ cd e
+$ ls
+584 i
+$ cd ..
+$ cd ..
+$ cd d
+$ ls
+4060174 j
+8033020 d.log
+5626152 d.ext
+7214296 k
diff --git a/day7/utils.py b/day7/utils.py
new file mode 100644
index 0000000..862e042
--- /dev/null
+++ b/day7/utils.py
@@ -0,0 +1,90 @@
+class File:
+    def __init__(self, name: str, size: int):
+        self.name = name
+        self.size = size
+        self.parent = None
+
+    def __str__(self):
+        return self.name
+
+
+class Dir:
+    def __init__(self, name: str):
+        self.name = name
+        self.contents = []
+        self.parent = None
+
+    def __str__(self):
+        return self.name
+
+    def add(self, thing):
+        thing.parent = self
+        self.contents.append(thing)
+
+    def get_dir(self, name: str):
+        for thing in self.contents:
+            if isinstance(thing, Dir) and thing.name == name:
+                return thing
+        return None
+
+    @property
+    def size(self):
+        return sum([thing.size for thing in self.contents])
+
+
+def parse_commands_to_tree(commands):
+    listing_contents = False
+
+    root = Dir("")
+    cur_dir = root
+
+    for line in commands:
+        if not line.split():
+            continue
+
+        words = line.split()
+        if words[0] == "$":
+            listing_contents = False
+
+            command = words[1]
+            try:
+                arg = words[2]
+            except IndexError:
+                arg = ""
+
+            if command == "cd":
+                if arg == "..":
+                    cur_dir = cur_dir.parent
+                elif arg == ".":
+                    continue
+                else:
+                    if not cur_dir.get_dir(arg):
+                        cur_dir.add(Dir(name=arg))
+
+                    cur_dir = cur_dir.get_dir(arg)
+            elif command == "ls":
+                listing_contents = True
+        elif listing_contents:
+            dir_or_size, name = words
+            if dir_or_size == "dir":
+                cur_dir.add(Dir(name=name))
+            else:
+                cur_dir.add(File(name=name, size=int(dir_or_size)))
+        else:
+            raise Exception(f"Unknown command: {line}")
+
+    return root
+
+
+def print_tree(tree):
+    output = []
+
+    def parse_directory(directory, depth):
+        for thing in directory.contents:
+            output.append("{}{} ({})".format(depth * 2 * " ", thing.name, thing.size))
+            if isinstance(thing, Dir):
+                parse_directory(thing, depth + 1)
+
+    parse_directory(tree, 1)
+
+    print("\n".join(output))