Solve day 6

src/day06.zig

@@ -0,0 +1,58 @@
+const std = @import("std");
+
+pub const input = @embedFile("input/day06.txt");
+const test_input1 = @embedFile("input/day06_test1.txt");
+const test_input2 = @embedFile("input/day06_test2.txt");
+const test_input3 = @embedFile("input/day06_test3.txt");
+const test_input4 = @embedFile("input/day06_test4.txt");
+const test_input5 = @embedFile("input/day06_test5.txt");
+
+const CharSet = std.StaticBitSet(26);
+
+fn ascii_to_bit(char: u8) error{InvalidChar}!u8 {
+    return switch (char) {
+        'a'...'z' => char - 'a',
+        else => error.InvalidChar,
+    };
+}
+
+fn find_unique_marker(comptime length: usize, line: []const u8) !?usize {
+    var right: usize = length;
+    while (right < line.len) : (right += 1) {
+        var charset = CharSet.initEmpty();
+        var left: usize = right - length;
+        while (left < right) : (left += 1) {
+            charset.set(try ascii_to_bit(line[left]));
+        }
+        if (charset.count() == length) {
+            return right;
+        }
+    }
+    return null;
+}
+
+pub fn solve_part1(data: []const u8) !usize {
+    var line = std.mem.trimRight(u8, data, "\n");
+    return (try find_unique_marker(4, line)).?;
+}
+
+pub fn solve_part2(data: []const u8) !usize {
+    var line = std.mem.trimRight(u8, data, "\n");
+    return (try find_unique_marker(14, line)).?;
+}
+
+test "solves part1" {
+    try std.testing.expectEqual(solve_part1(test_input1), 7);
+    try std.testing.expectEqual(solve_part1(test_input2), 5);
+    try std.testing.expectEqual(solve_part1(test_input3), 6);
+    try std.testing.expectEqual(solve_part1(test_input4), 10);
+    try std.testing.expectEqual(solve_part1(test_input5), 11);
+}
+
+test "solves part2" {
+    try std.testing.expectEqual(solve_part2(test_input1), 19);
+    try std.testing.expectEqual(solve_part2(test_input2), 23);
+    try std.testing.expectEqual(solve_part2(test_input3), 23);
+    try std.testing.expectEqual(solve_part2(test_input4), 29);
+    try std.testing.expectEqual(solve_part2(test_input5), 26);
+}

src/input/day06.txt

@@ -0,0 +1 @@
+rqwqtwwrmrqqrcrtrpppjrjgrgjgqgttgbbhppftpfpdpmpsstffqvfqvvdjjpllltqltqtrrzlllbldbdsdqqgpqggzccgbgnnmjmljmljldjldjjlnnhndhdmmslmslmlhmmntnrtnrnbrbqrqhqfftwftfsfzfcfrrzllchcwwtwstwwjwrjjfwwgzwzqzpzhzqhqbhqhssltsszhsszdssrwssdppjcpjjrwjwnwjnnzjjhsjhsjsjvvtffffqfflglwglgbgpbgbgghfghfhdfhdfhfssqppvlvslltwwhwvwpwgggnpnnmqnntqnnlhhdbhdbbtvvcrrcgrrdrvrjvvlmlnmndnmnrncnznsnsqnsswrwzwmwzzbpbhphqhpqpbpqpjpjvpvwpvwppdvdhdccqbccfncctrcrjcjjdsdhdnhhwpwlwwbmbhmbhhpzhhccvffqqnsqqmnnspnnpfpzppspgsppgbbdwbbdcchfhgfhfllljtllnjlnlddvcdvdqvvqwqppprtpthtthqqfbqqpfpzfpfcfsscrsccbgbngbbgdbbpgpqqlmqlmmgffqqqsbqbtblbwbqqvbqvbqvvnzvzpvvqhvqqtltptllbflbflbflltddlblflvfvbffmsffhlhshmmgbbgjjdndqqmqllzjzvvhjhnhcnchhznnhhppwqpwpffwvwzzppwpfwftwtnnqbnqnrnrzznffzzblzlvzlzrrszscsqcssbggcgvvddsttgqqgwgcclzzszddlvddvbddrlrcllrblrrhlldzdtdccqllsblsszlszzdllhjljhhhzhffdwfdwfddwdtdrtdtntddldsllqffdvdhdpdhdrdprprrhggdqgghggmwgmghhchlhmllrnrdrcrqccbqqfbqbccjpjhhvppcwpwffmmzzfqflfjfdfbfqqtmthmttwftwwpmpzplzzpvvgppsbpbccbtcbcddzbzwwmsscrcctgtgjgtjthhjzzcqqmmmvccwjcwjwzzwnnwgwtgwwbsbvbccrscccnggfjfwfjfrfsfddncdncndnqqwzzmssbdsbswswdddpdqdbddcvcmmwwssrtrrlddndmdtmtdmttwwmsmffwqwvwbwhbbqfqqgcqcmctctntjntnbnrbrmbbqtqccqbcbvbnbqnnghgbbmfmwmdwmdmpmwppdwpdwwnzwnwrnwrnntqnttcmcqqbrqrttsjtstcscpcspsnswsggrhggjrjjbhhbnbmmdlmddtqdtdrdwwjvjgjjdhjdddbwwsfflppbwbcbpbjjzqznnrwnnvmvjvwvqqrlljgjmjjqhjhwjhwjjsvsnvvlwlqqjpjjbsjjcddtfthffrqfrqrfqfrfllfzzqllztltnltntpttqmmgwmwwwjjdrjrzrlrwlwzzzzphpphvphvphvpvdvfdflljgglrlrqlrrfpfqpqnpqpmmblbflbfbpfpwpjwpjpbjpjmjljblldbllnrnjjjljrlrcrrgzgbbzrznzzhnzhhtmhmqhmqqnzzvfzvzfftjftfvvpmvppwzzhnzhzvvwzwwqcwctwwgrrtgglgngsgvgwvwpvpbbrvrvwrvwvbwwpsprrrcbbpqppfjjjqnjndnmddvsvlslmmwwdwcchmmrjmjwwsrwrhwwpcgmpmvbdmlmqbnblbbgtmtgqslnvcnmwrflrnwhqzrsnwhncwdvbcpjrqsscwzrjvslhscpvmqjnltwhshjmbhgttbzllrvpnhgdmwtddbwmpgbhrndpgwzfvqdmpcvhlnjnqbwqmshgwhmfjgsbscsjtfbfvmlljqwwjtnltbzjpcqdfmdldvmsnmzqmghcvhlpjzzszcpvldrflbcppzwgppfpbslplrqwgbfwpwbtbnrmbrrrpqndzvhmlhvtlnjvhdrhhvmwzjntsgffjsdpdlhnlslnbmbsmdsvpmpbjpjcwhbpfnhbmttfglglnnhhcqvbpvnrwcszwjsdhqwctrpgsrcbfpzhbnrbllrlflqdlgzwpwgwwvmbsppbcjcdltbgwfndqjlvndhtclfmwnqrbfvvqdzspfcslplhtmsqqtrcdvbhfscvnmzplcglwnzbvgflclclqmdgfzjqqrrmpcqrzgqcnzbmncmvdzrmmvfqrrqzqbjmjgjwmfbnmmgvmzsgjjspjqbvfhrdvllgqsffjnfqdthjbjwhwqdqhsnctwgbszvrsbwbpptcjjvftnhdmwmhtjrjrlrdrqjznhqftgtldnpbrlprjmplmwdbzqpmwwvcqccjlhqbhcjprvrfmmfmljwmbrlhcglthgbmrfmbpsztfcglpzlfbpjhmvcmvrprmvmrvvgbbllzschwshhfbnmgwrbhlqvsdjdmmbtjzthwssghtqvhtqcswdhbwhphhsrwhwwtslwvrhpgqfmftnrtqpwfqqdgftdlqfndjlzhvlrthnqdqrzpprdgwwqlplrmqtdqgbdntmjcjhlbbmctvnnhtppfbjpsbmndbdplqlfqfhzqvtqcvmprwbhdtjrqrqvmcssqnfqwtchmjfjlpwsghplbthdnbhfbhhphdmlmtjcvmzjbnqbfldrvlmjfnnrlsnwrtnrpfqdhchltmbvjzhgjwzblqdthmffztqvzzfszmdqdzlfpbfgjfdjqscrhvjflbllnlghncczrlpcbwpnmzcnqhbfnlmnbqvmwvbchwhlfcssctsdcwmtfdgbhljwprfncdgwlgzzmvfqrdsmlwbrmbmtzqqdqdpzvtbstscglrwdpndnstrhgjchnpzsvcjngmzsddwsbllpvqqzzjlmsbncbndqmqphzqzcngjzpfnjmsvngtcvhhjsssrnhjrsmvbsrdjcrppvgsqbqjzbrhjqlgmqfclbrdhwwjdlsjnmjcjrmsstngswrhmdqthprcbrndfpdjgpqtfmmfvbztqdhzhzbzhjjpfgnvrmspdvmhfvbvztmlrhfqfdcfnzzndlfldpfhrbjrwlwnprdmqjwppbrdjhpbvnrvjlrbwdwttzhqqgcclbwghbgrhcvwjrrchqgzztrjgrltcpdscjdfcphndfzdqsbpsjrljdnflfvrzcrjflddfgpvnpmdqbhzwbfrpzsnpbcbgfchvvmqpnfpvvdvhfnpbfzwmbnlpqzgrpwtsjbpzdrsfmnfqwqvpgnrjhmvmphlfdpfhdjljlzftdzdvhjrvjdctwfrctglwmrtdlrvmhcqvfvpgmstghczmvclptzspdsrlvrgvjtvflhsmqswdpqjrrnhgrggzmcpqsctqbhpqrsbstwzgzghqgltcpbrhbcdqlhfjhlcrnhrpjdzlzqqprvzntbjztqgdqqttmbpbcfbjmdjqsflbczmfnsjdzcnnmjjllhvwbwlgrlpvbffwjvctwnrsfqdnwntscpsjnshhdmcqmcpscrmzltldwlmfnbhbtprsgtsbvzfrsfpvmqjzjqqhwdjjzvbhrvtbscrcpzrqsbgfbpwqfmbsrlhhtntjmtrtlwqsdbmgtdlrwfdnmwwzlltbrjgghbstbnffzmzzdlcdgvmrzsjnqjvczmhrgwbrblrqfmzbbcnfsbfpgjsmptzbclfdnwfgbzlpbgqrdhdmfjdnlzczdpvtbzdmrthslngbrldllfcjplhglmwsfpqjnrgpgqfmbbwchbrqqsncfwnmgdmtchdhlzzqjvtvtvgqbtwvwpsjqwdqhrlfmdgdzchvfbcmqjllpjtnphwqvfwpcjmzqhsbwlcmbsgththrsjtnzlsrcptgtrfcwptbstcsdzbwjljzjztzbqsjdvwglpbpgdjtthjjmsnljltglqcszbzqmblfpncntjzzhmjffldcrcvjjswvzlfffrmsgjtpzggtlpfwpwbmhmggpnmzwrgdjrhglnhfdcjdfjtdjvrnlgqtfqmpgjcvcmnwhhbczwwntfbmgssglngqlttfpcznswvmbprsrzljtlwlljnbbrnwdvvlsbdv

src/input/day06_test1.txt

@@ -0,0 +1 @@
+mjqjpqmgbljsphdztnvjfqwrcgsmlb

src/input/day06_test2.txt

@@ -0,0 +1 @@
+bvwbjplbgvbhsrlpgdmjqwftvncz

src/input/day06_test3.txt

@@ -0,0 +1 @@
+nppdvjthqldpwncqszvftbrmjlhg

src/input/day06_test4.txt

@@ -0,0 +1 @@
+nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg

src/input/day06_test5.txt

@@ -0,0 +1 @@
+zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw

src/main.zig

@@ -5,6 +5,7 @@ const day02 = @import("day02.zig");
 const day03 = @import("day03.zig");
 const day04 = @import("day04.zig");
 const day05 = @import("day05.zig");
+const day06 = @import("day06.zig");
 const utils = @import("utils.zig");
 
 fn solve_day(comptime day_num: u8, day: anytype, stdout: anytype, timer: *std.time.Timer) !void {
@@ -42,6 +43,7 @@ pub fn main() !void {
     try solve_day(3, day03, &stdout, &timer);
     try solve_day(4, day04, &stdout, &timer);
     try solve_day(5, day05, &stdout, &timer);
+    try solve_day(6, day06, &stdout, &timer);
 
     try bw.flush();
 }
@@ -54,5 +56,6 @@ test {
     _ = day03;
     _ = day04;
     _ = day05;
+    _ = day06;
     _ = utils;
 }