Day 3

Y2022.cabal

@@ -25,8 +25,10 @@ library
         Util
         Days.D01
         Days.D02
+        Days.D03
     build-depends:
         base          ^>=4.18.0.0
+      , extra         ^>=1.7.14
       , megaparsec    ^>=9.4.0
       , text
 

app/Main.hs

@@ -7,6 +7,7 @@ import Print
 
 import qualified Days.D01 as D01
 import qualified Days.D02 as D02
+import qualified Days.D03 as D03
 
 import System.Environment (getArgs)
 
@@ -14,6 +15,7 @@ solutions :: [(Int, Day, FilePath)]
 solutions =
     [ (1, D01.day, "./data/01.in")
     , (2, D02.day, "./data/02.in")
+    , (3, D03.day, "./data/03.in")
     ]
 
 runAll :: [(Int, Day, FilePath)] -> IO ()
@@ -29,4 +31,4 @@ main :: IO ()
 main =
     getArgs >>= \case
         ["all"] -> header >> runAll solutions
-        _ -> header >> runAll [last (solutions)]
+        _ -> header >> runAll [last solutions]

data/03.in

@@ -0,0 +1,300 @@
+vGFhvGvvSdfwqhqvmCPnlFPnCNPcCFcWcr
+ZbWZDMgsTHsrNNLJcJnsJl
+HbBWQgZVZZBzbgZphwjqpmmVfdGmjG
+vvCJLGnthChvtrvCCnRbTRqRPRBtbTRfPRRl
+djZSgHNNwjqcdWlbcbfc
+pFgMSfpMfzMDZFSgSjGJQQnCvMCVLnnJQLGC
+gVhQWQpcWZVwwHVvFvnnnnDFdL
+lzbPlztjltztzSjfGcPdTHLTHFCnnHCLndFGGd
+jsNbzbczclttSlfbqlljRQMJRMMpJwRZhspZgJRM
+hLJvfGcNDttSGvJtvSSJcqbqFBBWbjQqDrqbjDDjjb
+lTswlzZdssgFpdPwZpMQnCjngCCjWBQBWWQqng
+PRZMpzPZTdVZTfJvFvLFRctJcf
+JHbQtHVHHLLbTJmmZddgdgwhllMNhhhTgg
+spqpNGDjDPMhCFChMj
+DBSDDGnpSDsDWqWczcvSqWvsBtJJLLZrRVZLJRbBZNVrBHrV
+GwGhfhPhpHccvwSwrTsmsCjDmqTfbDqjss
+tQntQcNRJMFnnVQFFctJqCsRmsTjjbDqDlTqTbWT
+NZdVBZZNFzMFNNNvGprZcLGPGrrpcP
+SvCPLrrlCSvZLrCPPBNPRvNLQBbpmbdggQTTfpfQgpgTqbbb
+HVjHwMVwWtdMGwtwMwdhDFgbJgJqTmFMfFfmmfTTpq
+whtHVcjDtHWtsWdwVGVHthDPzRrNSsCRLrLRlZNzZSNzNR
+rjrlCCBtbtntwPPt
+FvfJHqBJQWWgWgWLwnMwMLbzvhwTTp
+WqHgWqBFgGfQgHfVdQFfVfrDllSsRSDmVmRCZZmSSSSZ
+gjnppCgGHNPrqqmFnnbr
+tGltVlJRtLRlrqcJcqZDqBJc
+VvhLlvWltWdVltRTLTfgwSjGNHhggQNQNjps
+HDWjCNfQjmwgWhcwPPVbZGcpMb
+sFltFBRRSRJBSSsBlSSnRLPZbVGMVPZpMpPZpcMrFZMc
+BLTBsstlqBRRBSvJJBsHdgdDNHCQHvbdCjQNNW
+lRGzWLZNFwJVbVVGcJ
+HqqpjPvHQnJgVgTnbdTV
+rVvjBQHQrQhCrzlzWrRlDZ
+jZjTZRSjZnhGZhzGnG
+HbnPHrCbBDMnhcrVLWWLLWWg
+MBwbCNDDptwNMttjdSnsqSRSFFdjtj
+bSfvcsNsDdccHHQm
+ljrlplvBhDHDHHHHJl
+jgpzhrzRrvhFRFrzFnWfZtTwSWZPbbqNbsTqsW
+vvCTvcDzHcgtvWjvcDcvgBCgwTdPFPpwpwmTSwwmdPwZpfZh
+rNLMNVqLGNrVsRNJNsPnGnnfnpSFGdfddndd
+VPQsMbVsPbzzvgCzgv
+wPsrqprHQQZsChZn
+cjgFLwWDlDltfLmTCnmWCnZZChCQ
+FccccSLGFwjVlfVLLtgdSPSpMpBMdMBRRdHdBp
+mQQcpmCCprrfLQqZVGqLGv
+PtsJdsMtTTTvFqLTnnqbGZ
+HjldthsHWztJzstZhBcHDDgpNpCpmrpgSD
+lCmhDljDJgWggcnh
+LdQrbdTDQGfGLPdqqFrHwRJcWRHgHBWHBJ
+sLqsGtDqdGQfSTsqtfqqVMzjCzlvllZljNpCsMMl
+CfLCZCCqqHlhSSrrtpRjpL
+mWQbnQZVTWwNdwmDSbpbrFptjDrjRj
+PJWVnTWPVnnclqqBsCCZHP
+tqvtbNCgqJSgZgZvSncrrcGjBGhcnVcR
+DswGQQQdRcjBnRDn
+sMdlFMQQpfZbvlNtZGgN
+RMlPllHtrlrlcZLsZfLcfwdDGD
+QppnQhTBgwQDJsGzLQ
+gTjnmjvphDSNMbtMbtMRHNVr
+RHHcChrVVChCWQmRnMZmnmbTbGmFnqTT
+gpzpfpszDwvDDNdwjdstnSMMHGMqvZnFTTZqbq
+DsDdpfppwHsgJdjzfdDjdssLPlRccPQQrJcchPQWWQRhlQcr
+rsrjQjnRnQZZqMmMMVqs
+WTSTdvJLvTGJTGCMGvzBBpVVqqFVzBzVmf
+tTSJhGLJbJhLJRRbHPQbnHHMrl
+GGgMgBJHWHhLWMhWhgfrhgWLzmsmlzTtzHmsmlszRtszRVlT
+bvScppfcQfcQSFCQpnPqwwTdRTvmzVssvswtddsv
+ZDpqnPbQbPPnQbFbfSPSqbQJhGrjgMZBhWLrLrBBBBJWhg
+hQCCGCNhDmGFJsTt
+fcggBBpvBSrtsRTpRmpD
+wflWlBlfnvfWWgMNPPLhPnzhPmLQ
+pcGGTvVpcQLLzSPPPpVBVQwngNqgsJqgJgqSngsJMqJg
+RZDFGhtCDGmWfWsNdwJhnMgwswqJ
+ZCGjRGjZllFGHvvcTPjPTQpB
+FDVsWrFZnnnfNRJdgBBBMLsJLH
+wcThcTphvCThwTlblpzwGlpLRgHJWLgHLBHdHWJLBLWR
+mwcbPmClwlzlwvvbTmWbQSjZmZSrDnSNVZfVFnZf
+tMlttlFRSrcSFcwQSRwSzrMMPPGGPGLWgNfTNTcLPNPGBPPG
+pbZVCDTqnCjVDHnHVnhBPBBbhBhbhgLgmWLh
+qZCJZJqqjjCVvvRQltlzTrJtMMMw
+QvvdBDdMbdFFJrMMjjmjCfCntC
+lHTPsNLPcfVZLnfj
+GgsWpHPpTPWpNsGvgdnDbQRQFRbdQg
+jPNwllsVZjhslSjwGShZMdJDmmdmWLtMDDPHMPFd
+QbvpDrbBrtMbbHJmcH
+vznvzBRpBprQBqQZjNswwZDnSlGjZl
+PdNTzLQPLrVMzGcMtt
+FsSvDrvmrwDggHGwgV
+vlpZpZmfnmFTlTWJWdbrdh
+mZmnggMTSJrrmnrbmTbngJMtwPvwzzRvPGhQdGZPGPLvGvRd
+FFVBNHVlFlDfCsWwLwPzzhGPCvzhQv
+qBHLsDcfqFfDDfsFLNcNNBFsrgpMpnJSbnmTnrtmbMSqnpnr
+qjBNwBPNPspqddssbsTsMDhTDrThQb
+gvzZSZzFbgHnrHmn
+fcvfZcRSZFGfZcvFbGttcPfpVjWVwqBqdwNdwNNpqV
+RrTmtTrqznrnRCSqJrWlWDbhWVnfVDVWdclV
+QBBgHQGvHHQswLHQQLGLHdLhfhlZZFlsscVDZfWfDhVlZZ
+dLBMPpGPjLHPHPBHjjgQjHQztSJRztmrNCSCmSpmprrrrz
+HHWJgjjsJrPBWBjgWgDvbbvtbNDNVtttMPPp
+SnLTlhhNSntRVVLFVbbb
+ChqdcNTNqqJCrQrQrrBC
+BvfLLngFLDrrlDFDDnGmGlmzqzdGqMMWWwWW
+RVsPbsbVZbjctccCcsCSPmdNqMqMWddwqVzhhNHwHd
+tcsjPZRctZTSbbtSbtsSjZznnJfJBrfJgLvJJDDBvpTrgp
+LJJsNdtJQtbWRJQttjGhjVnjcnzcsczGqj
+MDPPlvCwrTlZfMMvTlPTdVcVhVVjchSBrjccSnnq
+lgZCvTTZfMgHLptdRgmR
+gCDrJRNgJDZRCwMgqGbtVVjTjlFbbTtR
+mccnfcnSQScdvdcQQQpWdnWSjPqTbFFlbPqbPVGNjTPjtN
+NnzmpWmBBzzpzDgwhDghrZrw
+wcbVDBQwVBFQLFQDQcqQcLcJfpHJjmljGgMHfcfgGgjf
+PtnWMtSnlgJmWWmm
+nThPtRnzntstvrtRPqDFLMLdDwBBFLQDBT
+zshqnVqTwqHqZQgZDSZjpFjFFF
+PsBRvttdcgFFBSmc
+GlPsbLtrvrrrtJlCTnVTlwwfnhwVqH
+CvVVnFwWZnZwJZMNlCMNMpbMrrQG
+cpghqzqqtzbGMjTNclGN
+PqLBsgqBsSfBffShVmvRVwWsFpwZVpsn
+LzsLSScvscqNdGdgddQjCDbzhpCDbRbhDpDDwDwt
+ZlMBBBnlMFVFHVMJflJjJBfhRnCbCDpRttRPDCbWpCRbpW
+mlrFmJrmscNGmsjm
+FqQjLRjfvTFvlPHHNPMBDDNDPR
+chWptpcWTzBPMsMMMBHW
+zcJghwJZpZcgnctccdzzpGQrbQbblFFlTCCFTbdCFCFq
+QcwNpCcQzpwtCGPPPnrGrfHfvN
+FgjhhhjMVFVjqRRqDBVBqvMZvdrHnPZWZvsnZHdWnv
+ShBFhDVghhTBgBBFRRgRCmCPCcpPbwCmLTcCmbpb
+ZzlzsBzZnWnsBhFRvfvvLfWqfvMv
+GgQGjjddHHPwpHpTGjPdHMvtvwJqLtJRFlRFRqMwLc
+dgbbdjpGGgTHGGgQgdpmpgblrBrhrhCBSSznChsVhBsmNB
+PhSwPdnpsmSWWcjjDFNqnc
+GJGCTLbTZTrlfflVLFchHDHHDFcVVN
+RhlhrllQZhCsPvRBvMtSvw
+GVgnrgTWGVGjLVjWSpvvNmPTmpQmzvhf
+tBbBDsFtszzSSbPZbh
+BqlqdcqSJtFMdMjWrnGCWRrWGG
+sJVJsQhMhPPSQMwdHRmmsmmwRmsr
+zLFjLDTBFNWWwrqrffldlRdFRq
+BLjzjTpzLpzWGTbQpMJvVMQwQhhMQM
+RqSztDRhJDLmRMLlfvsP
+dMdMMHZCsnbdvmbP
+VHcZVVcZTwTQpgHQcgFMFBpDDzBqqqDhqJSjSjJjSD
+rdMnMGjdHhfnjqWWDJPpGWPtvW
+PTBSQSSzZSBSCzQFFSlZTFSvcZpWWcJvtJppvZpLLcDVcv
+sgQCsBmmlFCPFFzTgTBgdNnrNndnMrrrfbrNjf
+bpZdggTjHbgLglpHjldvHpjdhTVzmhzzzFPzmhFsFQSFnhhN
+rPCDBcCCMPGcWDNNWQzQQSNQnNzQ
+fCCJtDtGGGfGBtGqBrrcfRBcvPwpLgdZZvHdljvqpvdwbpvl
+qpmsNldnlHlCqQlHsHNHwJpJMtwvvvjMvfWjpDtt
+TccVBScrzBzzTGPbVTPQhWjfMjwwRtJtjMtWDWWfDS
+FQFbzBGczGBFLnFmmqsCLg
+qpblblvpvJzStJDrhrnGrdhDfFqf
+ggNQNwBgmTcgCBTBTQQjNfDCnZRRRrRGCnrFfdnhrC
+mjVFHQTHNjTwcmpzJzHltltbSssS
+WChWmdcmzndhFcZrrbvrVMVssj
+NQLDlDplpSJGpLfRRMZVBBGjVsGbbjbBZsGv
+QNDfNqlpLgSfNfNgNfpgpqwndwWwnCCnnTFMdHndzn
+ZGRPTngTZMSGMGnhSgRjQHsPbqjmsWHQCQWbNN
+BFLLfpzVDBfDdlfQcsbVcNmQsqqbcC
+zFvdplLDLtzFmrrwMMtTrShZ
+nTdmnVCGqTsSBTqv
+HlMPwMlHfPSfBBmFBfSL
+trHHwRHRwMHPMJQJHnDhbdRhdpCZmChNnd
+lwHWjzplvHqWHGsMLsLwLfgdfLdg
+tPJNPQmQmSGcTtFmctGmSCBgsBBRbLBRVdLVLCBBLgVf
+FPtTPQNPrPPQctTcNPSQJJPDjlzplnGDDjWWplWHhGvpnr
+jwvvDbvsRsrrjrfvfrrZsPpCpmPJJPqlqWmzRJRTqq
+HdLttdSQHdLHMMtNdLMSTtHpCmPplWhCzmzmPWlJhlNplP
+BTSLtLLQtnVZDnffbwfw
+snvQdrtrQprWpgmGLp
+FhzwlwHccBcljFBSDmHmLpgRmPDCffWL
+zFhllqjczzwJqqSqlZMsvJgVNMTbssVNnQbb
+dLZHrWjWPFZWZnPjZttjddFnMDVMGJMQqvMVGVRVpjVpGVvv
+zhzTwTlfTwCsShSgNhfzsQQqvMQStQMDGJJGvGQVvq
+TTwCBfsfBwhzwTBCzlmHZdLmBBbtLnLbFnnF
+BhBRLFmlBlmhgShHmhSlZlFgvbQNwvcsvMCcsQCwNQvNMsBw
+ttWddDjrfjDcssscDbvH
+jfjfPWdzdfjdnWpjtrzqnhmJGJFhSJRHSmSmlqlHmq
+QvJTgvsvghHRHHNbZvNZTRSzBBCLrDqzrfDDtJSqSLBC
+cPPwdcFFPDwfFrBrFfFfrC
+nppwdplpRvllsgDH
+BGLLWLLwHVZwHnNhwsMsrqMqhh
+STlTpDpmjzmjjjgccqdsbNbBhlNnNMhsqs
+pjmgjfSDSzmSgFzRZQfRRZLBVLVtZZ
+WHjddztMtVLNNFFTmbFPFPRw
+bJnvpQfqccQJZfpcbvCphcFGDPFGRwDGDDGwGsmPFnPF
+rvffQJZJqrpZCJZJQrQpvBvStlSWSzVSWBbzBLzjtjWWWj
+SJFMSMGSDLTsFgHvHL
+mNzRrRRzjzqqgPHvLTHjlvWg
+ZLbRpRnRnCrbmnmrRRNnwbGfMwDwfDDdSVMdVJdd
+nsqTbhcDssPsPWsnchPJMSTSMmJMwTSTCJJfJw
+DHvFvvdHpvpGFHDMVVJVplCCVpggCl
+RdQjtvHtDQNGsZqzcqPqbNcq
+GFzRjczzQJnLjJvvTj
+mSfHrNHDzHDrDSSSBvTZLTNqWJWBWLlv
+PfgCmfPzDVrtHsddVMsRFcVFQM
+sfBgfBfBsHBHFGhsqfjgQZtQQMdZgbZQptbM
+rNLRSzRTrrvvLSTWGpjpNZdQPtGtMdNM
+wvSWLwzTGTCcwwwJwvwcrcRcVfFBqhhVhDqhBllBfFqBCDCs
+LbTpDTcMTSzzMLhScnDnSppNQwVNZFBVnFsrwQQZrQrQrN
+tJtJCRlGWljGWCtjJZVPsJBsVwQmrQNN
+fvHRftqjGfWGwtfGqvLTzDTzzzchSbMDTd
+JJhWZlhqLDHtBDrqrB
+bwwmfrSmbmFjVSFQwSdpDvGdpPnRvDtHpGtGPG
+VgFfcSQfFgmLLrNThllTZc
+QmfvrpnvrrJGnBSCFTBMSWFS
+NVMggbVPzCTgDFDD
+NRqHRZjVRZdRVdZwNPrMrchGhGpcGfvhQlHJ
+nlBdCldndlZTttSSBBccPfGWLLHcTTcWPbbW
+jpsFzFmzDzNzDGChGcGGmPQHQf
+CNzqvvVJNFqvgRtlqRtdnwSZ
+MJtDbNHDDpmVPJVzzjLm
+RslhvlfRTWvWWRwfllSZngmggznjSPznLjmSnz
+TlhffRwWQhChDqbBQLFHqNrb
+HWnmSbzflWltlzLfWWDzjMBvCjjCTCgcMvzBBB
+qRRRZJwhZFGdRNfghVjMVVgfcghC
+QFFqwNNNwdNZZpqqZfnDSHmmlDLtWtHWlQmD
+JrFdNTTLRBTJrFVrBNdVLFBdlHbzQQsQzbPJtpbtltWsHbQw
+gZffDfMlCfjCSqMcpHPWHszstzHjQwpb
+GMnvfGlfvSqvcMMDgDDcfnqSVFRdmTmVdNBTdmRmBFVnLLBT
+ZvRHtDcZntLZssMssQBrMdnC
+jglqlVdlbqgVWjJMbrrBCpmQBBfrpm
+GqVVPPjPNjFVllNjJjFDvzTLZRvcLRLvTGdGDv
+fDVzvVfzzZPMsMbb
+LHtBwLBdhFgdHLLthRwFGGMsmrHMmmbZSmqbMGGG
+bblRwbTRlllfVQnCQn
+fVZzjRzpzpVCRPZhVWQvvLsWWWFQlmjWmG
+JDHgJdtwbZqJqsWBBDLlQlvLms
+cHHtdbqwrqbbtSbTgSTcVCMRZnRRVNhVPNMPpfMc
+fCMPBBdpMpsqMssQccnV
+TlwGWDjDZHLjZHHlLGmnlnNcRllsJcqtsJRV
+ZHhZHThLLrGwjDDjLwGWWWSjPpbpzrvBFBFdBBbqvCbpFfpg
+bvDfDPtCVfFFVdWWpmLRmzWzzdBW
+jgZTghhjrGrsswrsghHrlgTGzSRmMLwpJMSMzWLLWRzpRRSc
+lpjTpGHlpsNGTHllHrCFnDNPtVnvfQtQtQNP
+BwlQcwZBwwwQNqJTrrsRGCDTNt
+bMpVPSfRvCbCtTqsCs
+dPSRfRpPPjjmLMgZBZBLZZwFQnZn
+TsVfggTqVnsLVTdTpmDdRhwPRtPRDRwD
+ljHBSWZvvFWvBFPppnQPwnpmzR
+MSHSjbBclBSjccLJgqgnLVqTbsTT
+zncfVgRzVJgnTfVqNHvZJZNJNMpHbdvH
+PCBpsLjPPmMGdHNdHBHZ
+jSLlrhLPDWLrPrDCLPCfnpzcVRFcRTnlVncntT
+ccvSgjHtRjcjSvjvSrBjzSHHwnJPbgwPPZVVVZnPpZlpwnlT
+ffqNqGGsGWqLTNqZwdndPnnJJpZVJW
+sNmqhsCMQsMTmjrcmrHrRj
+gWWWzNVJDwDzVWVDGbGNnhTnHLsmhmhfsQTNSmHd
+vtMPZvrZvqtqBHljrqSnnmTfLfdnQsjhjmhL
+MMPZPBqZCrBtvZcrBlDbGbbbzHJCbbRwgwDz
+hGSRhsMswhcNNGwhwncMnCqCJNrHJPJJrJtCJdqHJm
+BgVTzWBdTfCmfCJH
+dlbVFvvWVZhSRQDMnlhc
+WfpzBZmgJlQVGvWF
+wHSbrHwmccnrmrHsClGqFGbQjQjjQJQQGv
+SHPwwsRcrrNtrNSsphmZLzpfzhghZPdD
+DFDPRpmgbPQtmgBBQDDNJTMMBZsqsZGqGZTGCGSqWG
+fVvVVLcJVzlvzhqfSTCsZsMGMHqq
+zJdrrdnzcLlwczwbQmQngRDQPbtDpQ
+HDZZrpFqwRrQfBqhjjlVlQ
+czTgvvWPNgPGcTlsQflCVshClC
+PgNvtSJNvGVMMzNzgGvPGGLHFDdFdmZSZRdDdRrmpFwL
+SVHNVFVPBHJqHhgFCgzLmCwppm
+DvDdsGZljDlfdZnjnnZGMzLpRgLfMCLmzfPLhmgp
+jZDZlrvrZTrTrTQrDsjslHNJqtWbWHbqbPBWNVQWBJ
+NmGGBdWWJDJTTZHm
+hFVhcqFjncpcppSjqfppqDvzDDDbbDZvDZZbHfJgvJ
+jrPqnnHnqSPwPGWPdWst
+BfhbwMwbbPbHPPPlrdJjrlMJLrJVTd
+pnQnGnWDjnJdlJCh
+qshsWvpttzNNQDtzRRPvwfcPHBBBHwbw
+SHzGRQjhwwhGzjjwRjfBqpqbNCqNnnqqQqPlQC
+TZtgLmZgVmgdFgmZtdrbNqnqlNlpblnlrnBd
+DvgmvvZgmWJJjwHHhJSzps
+JjlrlJjPJgDjJjJnDRDjNwGGqMvSddvPvwQddqSVvq
+SLpphFLhFZhWLzvswwWqsqVVQWdv
+FSHtTLZpfzRDDrJgRNjT
+wjCMvrMlqqWHvWqddrHqgnBNhcffthhVLtpgLBnw
+GbQFZzZZphnpgNZV
+FhFzRTDRPzsRQGQGTFlllrJHjdsJlHMqjjHr
+LqDcTbmJcqSJSTmnrTcmJrfffplfjZsGZfGGZfQLdplj
+hWddgBvzWFZfPsQlGh
+RBWBRCdHtgHttVVzHBVNNNDwSTDcSSSbScDDwbwbnmRS
+FFPzwlZVVrzFFlFLVlllZdHCHPQMnJQQbhhChdhCbb
+BRRqGBgRfqvgvBDDDTRgghNCMMTQNNbVJMNJJdbbdT
+DfpgjGfsRWrFVzwLcs
+PMTSdSmFjhFpNTqvppvRBrRBrDqB
+HnZZznJbzGZGlZtZWHlJGcGcwMvQBsrwRDQvcDgrgDgrqRvq
+HGlGfnJZfMMCfNhm
+nRssqlqVRppVwdMMQwFgtRFz
+smTvLLTvvNLtwMMQNg
+CmPGBvZGWvBSGGDmTZjZlhpJcpHDJsbDnlrrprpl
+djcQGNQqdGdGqMCgndwgCLDMgW
+nvBvHpBppnvPPnJTBWLJVMwVfWJfCbfWgW
+hsHHpBsvRTHpsPszTBTTsRTslGqGqlcqlScnqmhZmmZSZSjl
+DddBHCmfWCBTDBHTHfMpzhzpJJMJsFrGrz
+tPVPmbnttjPnZvSvSbnmZPZPNpNGMpJNzzNrGJpvhsshMpFs
+mwnZcbmmStbVtVjbZVlcLTBlcLCRHRDWCWWW

src/Days/D03.hs

@@ -0,0 +1,34 @@
+{-# LANGUAGE ImportQualifiedPost #-}
+
+module Days.D03 where
+
+import Data.Char (ord)
+import Data.List (intersect)
+import Data.List.Extra (chunksOf)
+import Lib (Day (StringDay), definitive)
+
+type Intermediate = [String]
+
+halves :: [a] -> ([a], [a])
+halves l = splitAt (length l `div` 2) l
+
+priority :: Char -> Int
+priority c =
+    let o = ord c
+     in if o < ord 'a'
+            then o - ord 'A' + 26 + 1
+            else o - ord 'a' + 1
+
+part1 :: [String] -> Int
+part1 = sum . map (priority . head . uncurry intersect . halves)
+
+part2 :: [String] -> Int
+part2 = sum . map (priority . head . foldl1 intersect) . chunksOf 3
+
+day :: Day
+day =
+    StringDay
+        ( \s ->
+            let l = lines s
+             in Right (definitive $ part1 l, definitive $ part2 l)
+        )

src/Lib.hs

@@ -4,13 +4,13 @@
 
 module Lib where
 
-import Util (both, dupe)
+import Util (both)
 
 import Data.Function ((&))
 import Data.Text qualified as T
 import Data.Text.IO qualified as T
 import Data.Void (Void)
-import Text.Megaparsec qualified as M (Parsec, eof, errorBundlePretty, parse, sepEndBy1)
+import Text.Megaparsec qualified as M (Parsec, eof, errorBundlePretty, parse)
 
 data Answer where
     Answer :: (Show a) => a -> Answer

src/Print.hs

@@ -1,7 +1,6 @@
 module Print where
 
-import Data.Maybe (fromMaybe)
+import Lib (DayResult)
-import Lib (DayResult, PuzzleError (..))
 import Text.Printf (printf)
 
 printDR :: Int -> DayResult -> IO ()

src/Util.hs

@@ -5,6 +5,3 @@ dupe a = (a, a)
 
 both :: (a -> b) -> (a, a) -> (b, b)
 both f ~(x, y) = (f x, f y)
-
-mapSnd :: (b -> c) -> (a, b) -> (a, c)
-mapSnd f (a, b) = (a, f b)