Advent of code day 6

day6.c3

@@ -0,0 +1,44 @@
+module day6;
+import std::io;
+
+fn bool in_len(char* first, int len)
+{
+	char c = first[0];
+	for (int i = 1; i < len; i++)
+	{
+		if (first[i] == c) return true;
+	}
+	return false;
+}
+
+fn void find_packet_start(int check_len)
+{
+	File f;
+	f.open("signal.txt", "rb")!!;
+	defer catch(f.close());
+
+	while READ: (!f.eof())
+	{
+		@pool()
+		{
+			char[] line = f.tgetline();
+			int len = line.len;
+			for OUTER: (int i = 0; i < len - check_len; i++)
+			{
+				for (int j = 0; j < check_len; j++)
+				{
+					if (in_len(&line[i + j], check_len - j)) continue OUTER;
+				}
+				io::printfln("Packet start (%d): %d", check_len, i + check_len);
+				continue READ;
+			}
+			unreachable("Invalid data");
+		};
+	}
+}
+
+fn void main()
+{
+	find_packet_start(4);
+	find_packet_start(14);
+}

signal.txt

@@ -0,0 +1 @@
+rhghwwsmsgmgsmmmlzljllrddvsvhvhhnvvrcccwhhvgghchwhvwvcvrrrgtgrgdggfdgffshsllvvslsppglgvgwgswwcbcwbwrrbjbwjjtgjjdzdfdhfddrmmhqhpqhhqghhzssqzqccbwwffzvzffvtftddrbrtrrcjrrmmbmrrrlrppplmplmppfzpfpvpqvpqqdndpndnmnwmwjmwmwbbrhhmzmffwfqwfqwffppvfpvffnwwwwcbwbhbccvmmplmplmmlmplpprbpbllmhlhzhffngfnntrrsrprrvlllvjvmjvvppsrrfnrfnrfrfwrffrsfrflfltfllpfprrthhhnhqnnfwwcttvzzddqsddwpddnrnttvjttjjdjvdjvjnvnrvvchhschhlffjggtqgqnnvrnrsnrsnsvspsnncppvwvvtmmcqmcmscmsmwmvmpvvlqqmbqqlwwtgtztgttpjjbfjjzhzthhzssffwqqdmdcdlclrclrccbmmqjqmqcmmnnsvnntpphhdpdhhtbtdtffhzfhhpwhppwbppfspphdhggzqgzzffdsdfsszcscpscsqcssffhjhnhhlqqdbqqdmdsmddrfddndldgglvglvlggqlggjngjnnbffthhjbjpjnjmnmgmqqbjqjzjqzzzjffwttcnnzffmllcncmnnthnncttpgpnnjdjfftmmvqmqsqggfrfjjqbjbvvshvhphfhhljlfjjvcclzclctcmmfwfvwfvwwjvwvjjplpbpqqdvqqbhbdbnnsndssgffgsglssmfmjjfrjfrfttljldjdffjjdnjjlbbnrntrtfrttmhhndnsdsffgqqrpplvvfwvfvsfszzfzhfzzlttlctllrzrggvwvhhgnnlmnlmlpppdldqqdpdlplrpppjspspzzhphccgjjpmmwvwbwssnpssrzrwrhhmzhmhsmhmttrqrvqvcclggptpjpzpccltctppflfjffrtrjrhjhffhjfjbfjfqfqzffdtthwwjwzjzggsgzgqqjdqjddvgvsvnnqwqgwgtttfvfrfwrfwfwmwmqwmmmbzmzvzfvfrfvvgvtvptpbpwbwrbwrwffzzfgzfgfcfzcffjdjjvrvnnfmmtztffsggjcjzcjcssscnscnssmmwgwbbljlnjndnrrqwqjjjbnnmbmcmbcmbbvvmtvmmfcmcjcdcnnzfzfzqfzfvvmbvmmndnbnsnnlddqvvsnngvnnrttfbtbqqnwqqzfzfzccfmmgrrsbbhvvgjjhfhssjmmsjjzzbqblqlfqllwhlwwvvstvtfvttnncjjzcjcjrrsvrssmfsfczbrzrvscvmcmrjpzwhcqfrrzbljnmqlzbzqtmhrshlrjjpvhnsvtlhqggqwppsjpszmqwfqmlwbqzwcrggrvfbvztnflwvbrqcrqbcllswvsvhwjzpldgphwptfdnlgdlnbttjfzrdcfvpdhlssfsljvdjmwddbnrpqnnqlfdfdspbnjwqjwrgtnrftsqcfjpmqwgwhttggjwzvgbwlhmtmmjlwhssrgshzpbcnstzlqdshdhjfgqlsmqqhpwbscsjhfbhprvhmftqngjgdbcvfldqgqsjqjfdmcvsflwzflsjfssnjpbwffnsfcnrdsphbjpgghmcthgnzmpgppqjdvbztvhnwqzndntcpjdtwwhvsmgdcthpssszrqcbntgsznpghmbqddpqscntjprlwzhbzhjtwzbwwcldwdgsttzmtnstjnngzrgvhncdbgqnllfzbthldztsdwsngjzprbvrnbzrsghlgssbqfnbvhnhzwmmmtncvsdngdtwcbjlnnzbnlrnmrvnvsjnvzdqnggmsvljlvjznwdszcmblhrsjvczpnlhsmqjsmwhbjbplbtqsgqjdllhncwdgbvzwnmqvndcbfhnvtjnzmvjhwzvdldhgfwbqqzcnbflfnwntlhmqgdhmrgwqcpmsvfbmwhbtsbdlhcnbcbswvdfffgjvddrbpzpcwsrsjnfvmzhlvbdnwttnqrmzbnnntbfvptrlhjhwjcsbnhvtwtwzvgfnzjplthqjbsjjwzdtqqvblnbvgcmvrmnvmwfrhcqgvrcjlfzdlpbfvncbtfgvnsflbjzqqhczcmtbwqmrppmptfgzvfbmcslwlfrfpvvnvvnwfvvmmdzmmtjsgqdfhngtphtlfjqrtljgnthgnbbqfrnpfmpwhpzdvzmtswwdvcnpsdcqwjdwlvbsbmlwdsjbcbgcrfljshlvpngfmsrzlfhtfqgwbcctnzzhnqhdmqzdwthftwtmpbcmqvdcdtgvltbzmszzwwmhzlfvbdqnhjqgdmstsnhftcwzvvbmnhwvgqzscwcdjbdgfmvpjdzctwqwltbwjlgcblnnhpnmggbmvqpqtgqjzspgqzvcvsdbvjgjfzdzhfpbzjqljjcgldzgnlmtjcmfgdbqgglvjqrppwmhccvqzvsrjjvfhjprwdsqsnszfprznljtcsrtqhcrpljfrccflmbpvqtzgmzhjrlbnrmmsmmjbtzwpglqgdvvvjvnfzmplsmvlvcnjshvjwntclwgpznnzwhjssgdcjbzrmsgnfgcgphrhfvrfhzwdcvsplhbmqwhpmjvqlmschznbqblvhtqfgtdggmncndhhplnzjphccjmlmtdqnmnlnpnfqdstljqnsqbrjrtspvrwvdmwzlgdmsfvctzgtmgqhqqrzpbgplzcfdqnzhsqrbcvhsccshnnpvvrpvqzqsgzgmpzfvvrrcvhdtntnsqnjrbzlbzmpgwdqzbhtlrrhbwdqjlsfgdhmvgmgbqhwvljmmqfllqvvrznrlftgzjdcgtstjffqmgvffpvtctzpdqjfnmlcdzscntctmqhrtmhrlhbjzttrcvcnlhsrvtpbmdchhntnnpnzlvqqnsrjcmblcvphqgwshnjmplgvnbsmmdzgqcpqztjhhgjvtlbpdpdwlwmmfrdgcvzfbgvbgpbjnwsssvhszwplcgvpgjwdrwngbcdjwvlsfhqlrqzgrzpfgjstqfdbrpqdvrlgdwqcsrgvhctznjjlzsmzctsqtfnhhlpjgnltssglmlwshfbrgmjqbvsmqwvszdfsvhmtrfjgwjctpsmgzzjbpwsztnnvzrhwvvmhdpgdmwzsjprhlgzcdvhznlfgjqvcwqrplcfvzmthsdsnrtfvnlrmvwplmbdvdggmlvpgdgzhvzmvzwmptzsnfrcrjspccmqjpjmhjqgrjbdcdjbzjmphmcdvjqtmdshhjrqgjgsnpzfbfgpjpczwzvmclgzgztlvzmdbwgncnndjwhhhjnhtjdmcnrmnqbmjdrdcmtvcsmftqcfhsvhsfjmtzjpnwffggpfqlqmzlbhnnhbtgzfgnjvdzmvthqjrhzbwvhcjzcsmsvsctrqbltpcrpjjnsbjdbfjqfcbpcgcwtqsflmlwprjcwlmcjjgsfdpwcqvhjpsgvdgsfnscnbzsrmrbbvdrlltzplbvgqsdnplcvbhddbtmwnfmvqhqdlrtrmrmzmhlccgwgmbdppjqdjtwmvdzfsbsggrfstjwjpjnljffwffmqncfnthnhglwvsgvzmgbzhtdfpfmdwmcldthvsnqnptpmhqctblgfsszhcfbvcrggjdhthqvvvlldshvqwmvdtfslrhzvgdfwztrczdjgcfcgtmwnphqthlgpfnrqwcgpzwnlgdvsnvzftlnlfflfsmjzhrhqjctsbvtccwbfsdrnbhszzjhqndvwcsmffnstnfdfwpbgfztjmjngdczzlgpscjtshpmmmzlnqndsttbdgfjqcvbqlphwhlhgcvjbhjmtrfzlgpwdnvzrllndbhvhlngvhlszzdcrdgvrmjwcvhhtbhnjmdzgctqnpdlrnqjzbchjtcsggsczlgmvtqvzmsqvtrhtvdmzlcdddfnbvbsnrzvgzfqjtbhjqhdznrhbfbqwtnwvrfqsznbqfzfzfgmhvjjsgbbdbdtzswwlnfrq