競技プログラミングで見るRubyの豊かさ

!IBSVHVDIJ ڝٕϓϩάϥϛϯάͰݟΔ 3VCZͷ๛͔͞ େࡕ3VCZձٞɹ 4BU

!IBSVHVDIJ wגࣜձࣾӬ࿨γεςϜϚωδϝϯτ wڭһˠ8FCΤϯδχΞ wڝϓϩྺ ೥

ڝϓϩ "U$PEFS ͱ͸

ೖྗˠग़ྗ ͳΜ͔͢Δ

ͨͱ͑͹

ࠓ೔ͷ࿩ ɾ"U$PEFSͷ໰୊໰ௐ΂·ͨ͠ ɾͦͷத͔Β໰঺հ

େࣄʹ͍ͨ͠Ձ஋؍ Մಡੑ ֦ுੑ อकੑ

Մಡੑ ֦ுੑ อकੑ ಡΈʹ͘͘ ෳࡶͰ୹͘ ໰୊ʹಛԽͨ͠ ίονʂʂ େࣄʹ͍ͨ͠Ձ஋؍

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@ ))ͷ஋ΛٻΊ͍ͨ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@ ))ͷ஋ΛٻΊ͍ͨ ೖྗྫ 42 3 ग़ྗྫ 39

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@ ))ͷ஋ΛٻΊ͍ͨ

ϙΠϯτ จࣈϦςϥϧ? joinͷΤΠϦΞε*

ϙΠϯτ ίϚϯυͱ࣮ͯ͠ߦ evalͰअѱ͞Λԋग़

IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@ ))ͷ஋ΛٻΊ͍ͨ ࠶ܝ ΋ͬͱ୹͘ॻ͚ΔΑͱ͍͏ਓ͕͍ͨΒڭ͍͑ͯͩ͘͞ ໰୊

໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠

ೖྗྫ atcoder beginner contest IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠

ೖྗྫ atcoder beginner contest IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠ ग़ྗྫ
ABC

IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠

IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠ ΋͏গ͠୹͘Ͱ͖ͦ͏ ಡΈʹ͘͘

IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ໰୊ ͭͷ୯ޠ͕ۭന۠੾ΓͰ༩͑ΒΕΔɻ ֤୯ޠͷઌ಄Λͭͳ͛ɺେจࣈͰग़ྗ͍ͨ͠

ϙΠϯτ େจࣈ΁ͷม׵ord

ϙΠϯτ େจࣈ΁ͷม׵ord ڝϓϩͰ͸كʹΑ͘࢖͏ʂ

ϙΠϯτ ඪ४ग़ྗputc

໰୊ " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ೖྗྫ 9 AACCCACBB " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 "
# $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B ೖྗྫ 9 AACCCACBB 123456789 ग़ྗྫ 8
" # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ indexʹ߹ܭCZUF΋࢖ͬͯΔʂʂ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ $_ ͕3ՕॴʹݱΕΔͷ͸৑௕

໰୊ IUUQTBUDPEFSKQDPOUFTUTBCDUBTLTBCD@B " # $ͷΈ͔ΒͳΔ/จࣈͷจࣈྻ4 " # $͕ճҎ্ग़ݱ͢Δͷ͸Կจࣈ໨ʁ ׬੒

ϙΠϯτ Regexp#~ $_ͱͷؒͰϚονΛͱΔ

ϙΠϯτ ΠϯΫϦϝϯτ bit൓స ୯߲ԋࢉ -

·ͱΊ·͢

·ͱΊ ɾ͍ΖΜͳॻ͖ํ͕Ͱ͖Δ ɾϝιουͷ๛෋͞ ɾ߈ུຊʹࡌͬͯͳ͍ॻ͖ํΛ୳ָ͢͠͞

3VCZJTGVO ,ZPQSPJTGVOTP UBLFUIFDIBMMFOHF

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