Magic Caesar autodecipher

13May07

import Char
import List
charRot r w = let base = (if isUpper w then 65 else 97) in 
    if (isAlpha w) then chr (base + (mod ((ord w) - base +r) 26)) else w
strRot r w = map (charRot r) w
unRot w = [strRot r w | r<-[1..26]]
countString st = [length (filter (==(chr x)) (map toLower st)) | x<-[97..122]]
score w = sum $ zipWith (*) (map fromIntegral (countString w) )
[8.275745257452574e-2,1.3306233062330624e-2,
2.96239837398374e-2,3.848238482384824e-2,
0.13211043360433605,2.630420054200542e-2,
1.978319783197832e-2,5.9508807588075883e-2,
8.205962059620596e-2,1.3075880758807589e-3,
5.267615176151761e-3,4.563346883468835e-2,
2.640921409214092e-2,
6.775067750677507e-6,1.157520325203252e-2,
8.263550135501355e-2,2.1565040650406504e-2,
1.27710027100271e-3,
6.222560975609756e-2,7.654471544715447e-2,
9.862127371273713e-2,2.943428184281843e-2,
1.1646341463414634e-2,1.9173441734417346e-2,
2.0121951219512196e-3,2.005420054200542e-2,
6.741192411924119e-4]
autodeRot w = unlines $ map show $ sort [(score x, x)| x<-(unRot w)]
main = do {
    name <- getLine ;
    putStr (autodeRot name);

These are a few tests a friend did:

$ echo "WPE XP DPP TQ ESPDP SPFCTDETND LWW HZCV HPWW ZC YZE" |./magic

(2.167953929539295,”WPE XP DPP TQ ESPDP SPFCTDETND LWW HZCV HPWW ZC YZE”)

(2.1861212737127373,”ATI BT HTT XU IWTHT WTJGXHIXRH PAA LDGZ LTAA DG CDI”)

(2.5361686991869914,”LET ME SEE IF THESE HEURISTICS ALL WORK WELL OR NOT”)

$ echo SHUKDSV LWV D KROH, FDQ BRX GLJ WKDW KROH RU FDQW BRX?SHUKDSV LWV D KROH, FDQ BRX GLJ WKDW KROH RU FDQW BRX? | ./magic

(3.8078252032520323,”APCSLAD TED L SZWP, NLY JZF OTR ESLE SZWP ZC NLYE JZF?APCSLAD TED L SZWP, NLY JZF OTR ESLE SZWP ZC NLYE JZF?”)

(3.9856097560975607,”ETGWPEH XIH P WDAT, RPC NDJ SXV IWPI WDAT DG RPCI NDJ?ETGWPEH XIH P WDAT, RPC NDJ SXV IWPI WDAT DG RPCI NDJ?”)

(4.096321138211382,”QFSIBQT JUT B IPMF, DBO ZPV EJH UIBU IPMF PS DBOU ZPV?QFSIBQT JUT B IPMF, DBO ZPV EJH UIBU IPMF PS DBOU ZPV?”)

(4.201192411924119,”TIVLETW MXW E LSPI, GER CSY HMK XLEX LSPI SV GERX CSY?TIVLETW MXW E LSPI, GER CSY HMK XLEX LSPI SV GERX CSY?”)

(4.557330623306233,”PERHAPS ITS A HOLE, CAN YOU DIG THAT HOLE OR CANT YOU?PERHAPS ITS A HOLE, CAN YOU DIG THAT HOLE OR CANT YOU?”)

$ echo JG J VOEFSTUBOE UIF CBTJDT, NBZCF J DBO QVU BMM PG UIFN JOUP B CPY PS B DBO BOE TIBLF JU TP CBEMZ UIBU JU UVSOT JOUP TPNFUIJOH FMTF. | ./magic

(4.538712737127371,”MJ M YRHIVWXERH XLI FEWMGW, QECFI M GER TYX EPP SJ XLIQ MRXS E FSB SV E GER ERH WLEOI MX WS FEHPC XLEX MX XYVRW MRXS WSQIXLMRK IPWI.”)

(4.616466802168022,”UR U GZPQDEFMZP FTQ NMEUOE, YMKNQ U OMZ BGF MXX AR FTQY UZFA M NAJ AD M OMZ MZP ETMWQ UF EA NMPXK FTMF UF FGDZE UZFA EAYQFTUZS QXEQ.”)

(4.622029132791328,”JG J VOEFSTUBOE UIF CBTJDT, NBZCF J DBO QVU BMM PG UIFN JOUP B CPY PS B DBO BOE TIBLF JU TP CBEMZ UIBU JU UVSOT JOUP TPNFUIJOH FMTF.”)

(4.925511517615177,”TQ T FYOPCDELYO ESP MLDTND, XLJMP T NLY AFE LWW ZQ ESPX TYEZ L MZI ZC L NLY LYO DSLVP TE DZ MLOWJ ESLE TE EFCYD TYEZ DZXPESTYR PWDP.”)

(5.010033875338754,”XU X JCSTGHIPCS IWT QPHXRH, BPNQT X RPC EJI PAA DU IWTB XCID P QDM DG P RPC PCS HWPZT XI HD QPSAN IWPI XI IJGCH XCID HDBTIWXCV TAHT.”)

(5.256114498644987,”PM P BUKLYZAHUK AOL IHZPJZ, THFIL P JHU WBA HSS VM AOLT PUAV H IVE VY H JHU HUK ZOHRL PA ZV IHKSF AOHA PA ABYUZ PUAV ZVTLAOPUN LSZL.”)

(5.624457994579945,”IF I UNDERSTAND THE BASICS, MAYBE I CAN PUT ALL OF THEM INTO A BOX OR A CAN AND SHAKE IT SO BADLY THAT IT TURNS INTO SOMETHING ELSE.”)

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