Add solution for day 6

day6/input.txt

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+pjbjvjtjljplppjssvtvwtwptptztltbtrrjgrjrzrqrjrbrhbrhrlllbpbdbbzqqgsqshqssjjbsjbsbmbhhmchhrqrcqqbwbqwwqrrznnsbswwwdjwdwmmsvszzlbbgddbgdgfgttzjzrjzrjzzvrvqqgpqggtbgtgvvrhvhtvtjjbpjjfjhjbhbddbjjjmzmtmgmpgmmmljlnljjmpmbpmbmrrlhhlppdgdfgfbbqlbbtffjjgvvnpvpbpttqmmnhhgfgrrwhrrbnbznzccmbmvmmzszsvsbvbccsrslsjsbbtdtwtvttvpvzzvbzzwczwcczhzhwhjhjghgppgpgttdwdhwhphnppqmpqqhthcchdhmhnnbcnbcbbggbfblljttwsswspsggpjjzszcscsmcmdmnngzzhrzrbrhbhzbzvzgvgffnlnljlrrhchhsvhssmpmccncdnccgdgbglgtlggnllsvvpfvpfpbffsgglddjrrzzphhptprtppwrwffzllrbrmrpmpdmpdmpplpspcphcphhgmmqnmmvnmmdvmvsmmqjmmlmlbmlbmlltlptphpnncscbscbcggwhhgjgqjqmjmdjmdjdrrvgvvzlldgdnnvttmmpffdjjvvchcwwbhwbwzzlmlccrttcntccpcgccpgcpggdrrbtrthhlrrbqrrpspdsdldbldblbzbpbgggtngtgqqtwwdjjmmcrmcrcvclcddhllpzpdzzmccrtccfvffccfhccpscctbbbzqzvvllgwlgwgvwwjswjswsvvwhhvjvsjvjmmjhjrhrmrvrnrccmnmzzmdzzbtbvbqvvgzgcgvvvvlltvllbfbqqrppwhpwpffzddzdzwdzzrggmhmfhmhbbzjzsjzzhhjdhhdnndsnssnfffbmffwhwrhhmmbnnbrnrbrrtqtztnzzzzblbhbdhbbfmfqfmmsgszzvfzfmfwfnwfwggwngnqnwqnwqwvwqvwvdvrvjjfnjnmnfmmwzzltztjjqnnnmlmzlmmrcmclcqqhrhdhccdfdvfvccvtcvvdmmtmccwjjcbcrrjmrjrdrffgwwvbvlvsspwpsspzsschssmqsqmqmlqmmqgqfqcqjcjtthjttlddfvvwwjvvtpvvfsvffqnffznzqzszgzmmjttwztwzzhqqccqsqmqnmqqjhqhzhwhvhdddsndsdfftvffwlwnnmmdpmmnhhrqrrclcdlcddhcdcppgrprnpnptnpphgpbqfngdgzvgndwcgrwcsfmhzsvddhzbgjmvvdjjzswvgnpmvgdpwsgbgjzjpsrfdzdzjzzrpplbhsmgddqzjbdzdzltqqwqjzqvwfmcdppbdbprrwzhmnrqclzrnmdjnfbwmvdrwtpwvgscrqgpndqnzbjsbljcbthbpgdjdcdwfhpvjnbsfjdlrjldvvmtfdslrhlfwmvclqrljrqmmjgqfwmfgwdjzzptgcthvtgdswsqjrqvnzmtqldjjcqnfhtvbwhjqlvpptfwjrdpcwvzddgcjzvqbhtsnnnjqqmqlbgvqmvjhvvpbzcbdmhgmcjbfcccsvlzjztvjzrrlhtgwccdcgcptqlmdhmdhvqzfntbjqtsmvqgwsltqntgszllntrljfgfsghtbbcqrdgwqphmbqtzmjqccrgvqpqpchzjstdmmtvntwjqsbcqjgnhzlllcfbpgtgrhwwhqqdlgrlsbzbmchvjnsgpdnmqvtgwqjpgflqgfngjfcfwqzmvvgzmmhbgfnbzvzclwclqdcccgbrrzpwdtprgsvhbgsnbntgrvnzhrnzfzdmnlbnrbqvmjbwpgvjlhbcvsrlqmcsnlrvtfdwtvcbmlndgbctsnmtctjszlpddqmzbtphhhfznwbdfsgppmdmczmhmmrzpllfqqbgvlsrscpfgznhdhgrnnnvrchgvzlqbgvcfghjvlvrvpclfcshbmvglcfrjbzrbcjmjjrfgqthwfrqbgtjldmbnfwllspmwrvstvrltvrlvrtjvprgtgzjlrgclvjhqpfcwcdbdtzwdsdfrtsvtvgjmsszdfqlmhqqlzswjfndswlmhcrhglphvpnfjpbmggbwlmzjchpnrllbjpmgmzjjrqpqgsbrszqhdljcpnclvrvbntgtcdcmhtdhgslhpvdjpvrszfrjhsbvcvtfwvvgczprnpbhmnnlmctbtqdjspgvhvnhwvspwgnjvzllwlnjhfjwsslppmjbfbdnthcpzbcmnnbvhctgwgdvhvlrbltmdnlfcsncqgrmjprshdvvtvcccgzhszcjgczhmhtvmccjpchqshhdzjjhbfpzqdjszdhdvlmgctmwcjprwlsqbcqhlcrfdgnqzfdfvqslmqlppbsvbmjmfbrtdmpmtqvwvppcfzddjzhhzlrrnnhbrlhmzlqwftprfvctnfhfhfzrnrvggfqmqwcwszhtbfjncprgwcqbjlvtnrprlwwghswvprjmsbmqvwnnfggprndvshfvvwtrqjpwghgbppftgzhqjslfzhngwfsjnmjzdsjqgpmglwnjlcgmczgvndszrszcpnzqpbzjmgrfsbjlghwrbqsqdhlnhzsvsgbqhbcdffjlgrbdrrjvclzqpftlhdvvcrvlgvlpnjcqdcbdjtlwnldjhhhzrwsqlhlsztwrznfsszptlrhjmqwmnfwjtjwmmmtvwzhpmjgzgsscbddgvvhpcnhvnggzhbzvvjlmdftpbcsvtsttrvgghptmmcdclbdvmnsdntthfbdznbclwccnlzcvdwzrqgddjszvbdqcjppzrtpnrhfcvvwpjqczgqwzzzvzmlnlzqszvtllftthgwgftjzsndpzzcnqpcvmsdvvfrjdsvfclsqqhsjrrctfvdrlhfmhprjggdcmqrrbqtwnrllhhztvjgmzqszbvqfwsgllvhsvfrjffvdscwjzqlzlwdpgthddpgzjfdbdqpsnntwpslvsdpqfnsgcllszcjwvtqhwhpfrlfdgwrfmgfpjmvnstrmtfcvgwlqdfqvntltqtrmjjtwcthvwntqgvncssplnmvlnstlcphvlcmvjnstwldtntchcbmzmlzhgjfbrdlgzvqpgcndmfdnmcnwhmpdnpqstfddddcrpgrpfwfbzjqtnzwwqpzrqpmrjpfznrndfgwhtlvrcrphqfjzjbttwhgnsngqwvnsbvcqtjlmhvmnmnnmjcmlpnpgmrqsbmgljvsfqvrlljqzmzqqbgpvcrwdjmgsglssjswmnvtshhfqjhqmfmvcjwfpwsppgtrqsbhhcdljnjphnjszqpvdplbwzpwmmpwfhmhngtllzqvpmgdctmfqwwqjszssmjhwnrjdtmmvpdnwlqtcbpfcmwtbjmmsmmdpqgzdhsblgjmjbpzgqvqhnggtwmhztbbhlflllgwblncjjsngdgvsfdmsbsvlpnjjzqqbzhsqclmjnnmmwlpvtgwqmcgmrqdwdddlgbvhntbztbjnqhdlggnzwsdtdzprgddhtcttjrcpszgchtfwqjsdlnbntfwqpzpfsqrqjhthmcfszwtwcqwbvfzdnrrpmzjdrhsgmhfbsldvcrjdwvpqpszzlvbptljgvccqsdhhnztjpghbvhfptgplqdvldjzfthpspwvgljwnnndwrqzbrstnqbvrrcghssnrpvtrhmvcmbngwndzfswmgjwnnzqdcjhpthcgvthsnwqzrnzrvdjmctchhsbnrtvctzqfpcjhzmhnfjlqftbjztfbcppgmwvrzzrvlcpnpwwpvtcpdplrcfpgfqjtlfjtphhpcltwqcbqbznbtjrtdrpgtvzmgsclhpptrssqqbctdrftqzmwjmrmjtgmjmsnbnspjvcqpqnmgzgjrmfhghvsfsdqnbdjsbcpczsdswdcvhfzlgpzbtmztcnbpcvjnlcdmmlbtwzsfqtfnlrwjtwmgslcgptgbdsfwdhppvfwbbgdfdqtrbncbznmqtchzsdzlhlhjnnbpdvnnfjrdfbdqmvcb

day6/part1.py

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+"""
+--- Day 6: Tuning Trouble ---
+
+The preparations are finally complete; you and the Elves leave camp on
+foot and begin to make your way toward the star fruit grove.
+
+As you move through the dense undergrowth, one of the Elves gives you a
+handheld device. He says that it has many fancy features, but the most
+important one to set up right now is the communication system.
+
+However, because he's heard you have significant experience dealing with
+signal-based systems, he convinced the other Elves that it would be okay
+to give you their one malfunctioning device - surely you'll have no
+problem fixing it.
+
+As if inspired by comedic timing, the device emits a few colorful sparks.
+
+To be able to communicate with the Elves, the device needs to lock on
+to their signal. The signal is a series of seemingly-random characters
+that the device receives one at a time.
+
+To fix the communication system, you need to add a subroutine to the
+device that detects a start-of-packet marker in the datastream. In the
+protocol being used by the Elves, the start of a packet is indicated by
+a sequence of four characters that are all different.
+
+The device will send your subroutine a datastream buffer (your puzzle
+input); your subroutine needs to identify the first position where the
+four most recently received characters were all different. Specifically,
+it needs to report the number of characters from the beginning of the
+buffer to the end of the first such four-character marker.
+
+For example, suppose you receive the following datastream buffer:
+
+    mjqjpqmgbljsphdztnvjfqwrcgsmlb
+
+After the first three characters (mjq) have been received, there haven't
+been enough characters received yet to find the marker. The first time a
+marker could occur is after the fourth character is received, making the
+most recent four characters mjqj. Because j is repeated, this isn't a
+marker.
+
+The first time a marker appears is after the seventh character arrives.
+Once it does, the last four characters received are jpqm, which are all
+different. In this case, your subroutine should report the value 7,
+because the first start-of-packet marker is complete after 7 characters
+have been processed.
+
+Here are a few more examples:
+
+    bvwbjplbgvbhsrlpgdmjqwftvncz: first marker after character 5
+    nppdvjthqldpwncqszvftbrmjlhg: first marker after character 6
+    nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg: first marker after character 10
+    zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw: first marker after character 11
+
+How many characters need to be processed before the first
+start-of-packet marker is detected?
+"""
+
+
+def main():
+    with open("input.txt", "r", encoding="utf-8") as input_file:
+        data_stream = input_file.read()
+
+    read_chars = []
+
+    for index, char in enumerate(data_stream):
+        read_chars.append(char)
+
+        # We need 4 unique characters, so as long as less than 4 chars
+        # were read, just continue loading characters.
+        if len(read_chars) < 4:
+            continue
+
+        # We only need the last 4 characters to compare, so if we load
+        # a fifth char we can pop the oldest out of the list.
+        if len(read_chars) == 5:
+            read_chars.pop(0)
+
+        if len(set(read_chars)) == 4:
+            print(f"After {index+1} chars")
+            break
+
+
+if __name__ == "__main__":
+    main()

day6/part2.py

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+"""
+--- Part Two ---
+
+Your device's communication system is correctly detecting packets, but
+still isn't working. It looks like it also needs to look for messages.
+
+A start-of-message marker is just like a start-of-packet marker, except
+it consists of 14 distinct characters rather than 4.
+
+Here are the first positions of start-of-message markers for all of the
+above examples:
+
+    mjqjpqmgbljsphdztnvjfqwrcgsmlb: first marker after character 19
+    bvwbjplbgvbhsrlpgdmjqwftvncz: first marker after character 23
+    nppdvjthqldpwncqszvftbrmjlhg: first marker after character 23
+    nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg: first marker after character 29
+    zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw: first marker after character 26
+
+How many characters need to be processed before the first
+start-of-message marker is detected?
+"""
+
+
+def main():
+    with open("input.txt", "r", encoding="utf-8") as input_file:
+        data_stream = input_file.read()
+
+    read_chars = []
+
+    for index, char in enumerate(data_stream):
+        read_chars.append(char)
+
+        # We need 14 unique characters, so as long as less than 14 chars
+        # were read, just continue loading characters.
+        if len(read_chars) < 14:
+            continue
+
+        # We only need the last 4 characters to compare, so if we load
+        # a fifth char we can pop the oldest out of the list.
+        if len(read_chars) == 15:
+            read_chars.pop(0)
+
+        if len(set(read_chars)) == 14:
+            print(f"After {index+1} chars")
+            break
+
+
+if __name__ == "__main__":
+    main()

day6/testinput.txt

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+mjqjpqmgbljsphdztnvjfqwrcgsmlb