commit 0f0e042ff46d956bcd06d885859518ba5dbe2662
parent 0d74166d177df1853679d83d11c45bfd0358a4a0
Author: Louis Burda <quent.burda@gmail.com>
Date: Sat, 12 Dec 2020 13:50:57 +0100
added day 12
Diffstat:
7 files changed, 1036 insertions(+), 0 deletions(-)
diff --git a/lib/aoc.zig b/lib/aoc.zig
@@ -45,3 +45,66 @@ pub fn gen_main(comptime part1: part_type, comptime part2: part_type) fn () anye
};
return impl.main;
}
+
+pub const Pos = struct {
+ x: i64,
+ y: i64,
+ const Self = @This();
+
+ pub fn add(self: Self, other: Self) Self {
+ return Self{ .x = self.x + other.x, .y = self.y + other.y };
+ }
+
+ pub fn mult(self: Self, val: i64) Self {
+ return Self{ .x = self.x * val, .y = self.y * val };
+ }
+};
+
+pub const Dir = struct {
+ pub const East = Pos{ .x = 1, .y = 0 };
+ pub const West = Pos{ .x = -1, .y = 0 };
+ pub const South = Pos{ .x = 0, .y = -1 };
+ pub const North = Pos{ .x = 0, .y = 1 };
+
+ pub const Name = enum {
+ EAST = 0, WEST = 1, SOUTH = 2, NORTH = 3
+ };
+ pub const dirs = [_]Pos{ East, South, West, North };
+
+ pub fn get(name: Name) Pos {
+ return dirs[@enumToInt(name)];
+ }
+
+ pub fn nextCW(dir: usize, offset: usize) usize {
+ return (dir + @intCast(u32, offset)) % @intCast(u32, dirs.len);
+ }
+
+ pub fn nextCCW(dir: usize, offset: usize) usize {
+ const constrained = offset % dirs.len;
+ if (dir >= constrained) {
+ return dir - constrained;
+ } else {
+ return dirs.len - (constrained - dir);
+ }
+ }
+
+ const cos90vs = [_]i32{ 1, 0, -1, 0 };
+ const sin90vs = [_]i32{ 0, 1, 0, -1 };
+
+ pub fn rotCW(pos: Pos, offset: usize) Pos {
+ const constrained = (4 - offset % 4) % 4;
+ return Pos{
+ .x = cos90vs[constrained] * pos.x - sin90vs[constrained] * pos.y,
+ .y = sin90vs[constrained] * pos.x + cos90vs[constrained] * pos.y,
+ };
+ }
+
+ pub fn rotCCW(pos: Pos, offset: usize) Pos {
+ const constrained = offset % 4;
+ std.debug.print("{}\n", .{constrained});
+ return Pos{
+ .x = cos90vs[constrained] * pos.x - sin90vs[constrained] * pos.y,
+ .y = sin90vs[constrained] * pos.x + cos90vs[constrained] * pos.y,
+ };
+ }
+};
diff --git a/src/day12/input b/src/day12/input
@@ -0,0 +1,786 @@
+L90
+F67
+R270
+W1
+R180
+F5
+E5
+F59
+E4
+L180
+F70
+S2
+F35
+N3
+E5
+F58
+L90
+N1
+F46
+R90
+S1
+R90
+E1
+L180
+W4
+F99
+N2
+F84
+N1
+R90
+N5
+W4
+F26
+E1
+F97
+N1
+F36
+W1
+F21
+S4
+F31
+S3
+F76
+S5
+S1
+L90
+S4
+W4
+R90
+E4
+F14
+R90
+S2
+R90
+S3
+F21
+N1
+W4
+S4
+E1
+L180
+N5
+F30
+N3
+F4
+N5
+F100
+N2
+R270
+E1
+S1
+F79
+N4
+F72
+W4
+F50
+L90
+W5
+S4
+E2
+N5
+E4
+S5
+W5
+L90
+E4
+L90
+S4
+E4
+R90
+N1
+W5
+R270
+W5
+N4
+R180
+E5
+F86
+L90
+W3
+F79
+W5
+F87
+L180
+N4
+E2
+S1
+W3
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+F31
+W2
+N1
+F86
+E1
+L90
+L90
+F2
+E3
+F8
+L90
+F54
+W3
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+E3
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+F44
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+R90
+W1
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+E1
+F99
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+E5
+F82
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+N3
+F17
+S5
+E4
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+E1
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+R90
+F32
+N1
+R90
+F84
+E4
+W4
+R180
+E4
+R90
+N1
+F26
+W4
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+F96
+E5
+S2
+F86
+R90
+F95
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+F81
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+W4
+F44
+N3
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+N5
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+E5
+N4
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+S2
+E3
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+R90
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+F4
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+E3
+F96
+L180
+F53
+W5
+L90
+F12
+N2
+F100
+W2
+R270
+S1
+F37
+E4
+S1
+E1
+L270
+W2
+S5
+F10
+L90
+N3
+F63
+L90
+F96
+S3
+W1
+N4
+R180
+E2
+F51
+L90
+N4
+F27
+W3
+N5
+R90
+N4
+L180
+F4
+N1
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+F71
+E5
+S5
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+L90
+F98
+E3
+N4
+E5
+R90
+F75
+S1
+F19
+E2
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+S3
+L90
+F29
+R180
+F88
+R180
+F3
+S2
+E5
+F16
+L90
+E1
+S2
+E3
+F28
+E5
+F22
+L180
+S2
+E1
+S1
+F6
+E2
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+F14
+R90
+N4
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+F77
+L90
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+S3
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+N1
+W1
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+F31
+N5
+W5
+R90
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+F40
+N2
+E1
+S3
+L90
+E5
+R180
+E2
+L90
+F88
+R90
+F45
+R270
+W4
+F67
+W4
+S1
+W4
+F65
+L90
+F19
+R90
+F83
+S1
+R90
+E2
+R180
+F78
+E1
+E1
+L180
+S1
+E1
+N4
+W5
+F98
+L90
+E4
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+N2
+E1
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+N5
+L90
+S3
+F52
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+F55
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+F56
+S5
+E1
+R90
+F97
+E5
+N4
+L90
+E1
+N1
+W1
+N4
+L270
+F7
+N3
+L90
+W3
+L270
+F27
+E2
+N5
+F90
+N3
+R90
+F79
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+L90
+W5
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+F9
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+F50
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+L270
+W3
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+W1
+F17
+N2
+L180
+N1
+W4
+R180
+F10
+N3
+W3
+L90
+E2
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+L90
+N3
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+N3
+F19
+E5
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+E1
+F34
+F2
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+F14
+R90
+S4
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+E5
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+F66
+E3
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+N5
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+F41
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+F31
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+F43
+S3
+F91
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+F2
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+F20
+N2
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+F21
+W4
+N2
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+F42
+S3
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+E5
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+L90
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+E2
+N2
+F42
+E3
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+W4
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+L90
+R90
+F48
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+E5
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+N5
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+N5
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+F83
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+N3
+W5
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+F68
+N2
+W5
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+E1
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+R90
+F45
+E5
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+W5
+S4
+F5
+L180
+N1
+R90
+S4
+E3
+F22
+R180
+W4
+L180
+S3
+L90
+N5
+E5
+N1
+F6
+S5
+W1
+F86
+R180
+S1
+R90
+E5
+N2
+L90
+W4
+N1
+W3
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+F1
+R180
+F94
+L90
+E5
+F7
+R90
+F72
+R90
+N3
+N1
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+N4
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+N5
+E1
+N1
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+F8
+N4
+E2
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+S3
+L90
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+F54
+E1
+F100
+N2
+F20
diff --git a/src/day12/input-test b/src/day12/input-test
@@ -0,0 +1,5 @@
+F10
+N3
+F7
+R90
+F11
diff --git a/src/day12/main.zig b/src/day12/main.zig
@@ -0,0 +1,60 @@
+const std = @import("std");
+const aoc = @import("aoc");
+const Pos = aoc.Pos;
+const Dir = aoc.Dir;
+
+const Ship = struct { pos: Pos, waypoint: Pos, dir: usize };
+
+fn part1(allocator: *std.mem.Allocator, input: []u8, args: [][]u8) !void {
+ var ship = Ship{ .pos = Pos{ .x = 0, .y = 0 }, .waypoint = Pos{ .x = 0, .y = 0 }, .dir = 0 };
+ var lineit = std.mem.tokenize(input, "\n");
+ while (lineit.next()) |line| {
+ const val = try std.fmt.parseInt(u32, line[1..], 10);
+ switch (line[0]) {
+ 'N' => ship.pos = ship.pos.add(Dir.North.mult(val)),
+ 'S' => ship.pos = ship.pos.add(Dir.South.mult(val)),
+ 'E' => ship.pos = ship.pos.add(Dir.East.mult(val)),
+ 'W' => ship.pos = ship.pos.add(Dir.West.mult(val)),
+ 'L' => ship.dir = Dir.nextCCW(ship.dir, @divExact(val, 90)),
+ 'R' => ship.dir = Dir.nextCW(ship.dir, @divExact(val, 90)),
+ 'F' => ship.pos = ship.pos.add(Dir.dirs[ship.dir].mult(val)),
+ else => {
+ return aoc.Error.InvalidInput;
+ },
+ }
+ }
+
+ std.debug.print("{}\n", .{std.math.absCast(ship.pos.x) + std.math.absCast(ship.pos.y)});
+}
+
+fn part2(allocator: *std.mem.Allocator, input: []u8, args: [][]u8) !void {
+ var ship = Ship{ .pos = Pos{ .x = 0, .y = 0 }, .waypoint = Pos{ .x = 10, .y = 1 }, .dir = 0 };
+ var lineit = std.mem.tokenize(input, "\n");
+ while (lineit.next()) |line| {
+ const val = try std.fmt.parseInt(u32, line[1..], 10);
+ switch (line[0]) {
+ 'N' => ship.waypoint = ship.waypoint.add(Dir.North.mult(val)),
+ 'S' => ship.waypoint = ship.waypoint.add(Dir.South.mult(val)),
+ 'E' => ship.waypoint = ship.waypoint.add(Dir.East.mult(val)),
+ 'W' => ship.waypoint = ship.waypoint.add(Dir.West.mult(val)),
+ // WORKAROUND for language bug (parameter is implicitly passed as reference and assignment order)
+ 'L' => {
+ var new = Dir.rotCCW(ship.waypoint, @divExact(val, 90));
+ ship.waypoint = new;
+ },
+ 'R' => {
+ var new = Dir.rotCW(ship.waypoint, @divExact(val, 90));
+ ship.waypoint = new;
+ },
+ 'F' => ship.pos = ship.pos.add(ship.waypoint.mult(val)),
+ else => {
+ return aoc.Error.InvalidInput;
+ },
+ }
+ std.debug.print("{} {} {} {} {}\n", .{ line, ship.waypoint.x, ship.waypoint.y, ship.pos.x, ship.pos.y });
+ }
+
+ std.debug.print("{}\n", .{std.math.absCast(ship.pos.x) + std.math.absCast(ship.pos.y)});
+}
+
+pub const main = aoc.gen_main(part1, part2);
diff --git a/src/day12/part1 b/src/day12/part1
@@ -0,0 +1,57 @@
+--- Day 12: Rain Risk ---
+
+Your ferry made decent progress toward the island, but the storm came in faster than anyone
+expected. The ferry needs to take [1m[37mevasive actions[0m!
+
+Unfortunately, the ship's navigation computer seems to be malfunctioning; rather than giving a route
+directly to safety, it produced extremely circuitous instructions. When the captain uses the PA
+system to ask if anyone can help, you quickly volunteer.
+
+The navigation instructions (your puzzle input) consists of a sequence of single-character
+[1m[37mactions[0m paired with integer input [1m[37mvalues[0m. After staring at them for a few
+minutes, you work out what they probably mean:
+
+
+ - Action [1m[37mN[0m means to move [1m[37mnorth[0m by the given value.
+ - Action [1m[37mS[0m means to move [1m[37msouth[0m by the given value.
+ - Action [1m[37mE[0m means to move [1m[37meast[0m by the given value.
+ - Action [1m[37mW[0m means to move [1m[37mwest[0m by the given value.
+ - Action [1m[37mL[0m means to turn [1m[37mleft[0m the given number of degrees.
+ - Action [1m[37mR[0m means to turn [1m[37mright[0m the given number of degrees.
+ - Action [1m[37mF[0m means to move [1m[37mforward[0m by the given value in the direction the
+ship is currently facing.
+
+
+The ship starts by facing [1m[37meast[0m. Only the L and R actions change the direction the ship
+is facing. (That is, if the ship is facing east and the next instruction is N10, the ship would move
+north 10 units, but would still move east if the following action were F.)
+
+For example:
+
+F10
+N3
+F7
+R90
+F11
+
+These instructions would be handled as follows:
+
+
+ - F10 would move the ship 10 units east (because the ship starts by facing east) to [1m[37meast
+10, north 0[0m.
+ - N3 would move the ship 3 units north to [1m[37meast 10, north 3[0m.
+ - F7 would move the ship another 7 units east (because the ship is still facing east) to
+[1m[37meast 17, north 3[0m.
+ - R90 would cause the ship to turn right by 90 degrees and face [1m[37msouth[0m; it remains at
+[1m[37meast 17, north 3[0m.
+ - F11 would move the ship 11 units south to [1m[37meast 17, south 8[0m.
+
+
+At the end of these instructions, the ship's Manhattan distance (sum of the absolute values of its
+east/west position and its north/south position) from its starting position is 17 + 8 =
+[1m[37m25[0m.
+
+Figure out where the navigation instructions lead. [1m[37mWhat is the Manhattan distance between
+that location and the ship's starting position?[0m
+
+
diff --git a/src/day12/part2 b/src/day12/part2
@@ -0,0 +1,49 @@
+--- Part Two ---
+
+Before you can give the destination to the captain, you realize that the actual action meanings were
+printed on the back of the instructions the whole time.
+
+Almost all of the actions indicate how to move a [1m[37mwaypoint[0m which is relative to the
+ship's position:
+
+
+ - Action [1m[37mN[0m means to move the waypoint [1m[37mnorth[0m by the given value.
+ - Action [1m[37mS[0m means to move the waypoint [1m[37msouth[0m by the given value.
+ - Action [1m[37mE[0m means to move the waypoint [1m[37meast[0m by the given value.
+ - Action [1m[37mW[0m means to move the waypoint [1m[37mwest[0m by the given value.
+ - Action [1m[37mL[0m means to rotate the waypoint around the ship [1m[37mleft[0m
+([1m[37mcounter-clockwise[0m) the given number of degrees.
+ - Action [1m[37mR[0m means to rotate the waypoint around the ship [1m[37mright[0m
+([1m[37mclockwise[0m) the given number of degrees.
+ - Action [1m[37mF[0m means to move [1m[37mforward[0m to the waypoint a number of times equal
+to the given value.
+
+
+The waypoint starts [1m[37m10 units east and 1 unit north[0m relative to the ship. The waypoint
+is relative to the ship; that is, if the ship moves, the waypoint moves with it.
+
+For example, using the same instructions as above:
+
+
+ - F10 moves the ship to the waypoint 10 times (a total of [1m[37m100 units east and 10 units
+north[0m), leaving the ship at [1m[37meast 100, north 10[0m. The waypoint stays 10 units east
+and 1 unit north of the ship.
+ - N3 moves the waypoint 3 units north to [1m[37m10 units east and 4 units north of the ship[0m.
+The ship remains at [1m[37meast 100, north 10[0m.
+ - F7 moves the ship to the waypoint 7 times (a total of [1m[37m70 units east and 28 units
+north[0m), leaving the ship at [1m[37meast 170, north 38[0m. The waypoint stays 10 units east
+and 4 units north of the ship.
+ - R90 rotates the waypoint around the ship clockwise 90 degrees, moving it to [1m[37m4 units east
+and 10 units south of the ship[0m. The ship remains at [1m[37meast 170, north 38[0m.
+ - F11 moves the ship to the waypoint 11 times (a total of [1m[37m44 units east and 110 units
+south[0m), leaving the ship at [1m[37meast 214, south 72[0m. The waypoint stays 4 units east and
+10 units south of the ship.
+
+
+After these operations, the ship's Manhattan distance from its starting position is 214 + 72 =
+[1m[37m286[0m.
+
+Figure out where the navigation instructions actually lead. [1m[37mWhat is the Manhattan distance
+between that location and the ship's starting position?[0m
+
+
diff --git a/src/day13/main.zig b/src/day13/main.zig
@@ -0,0 +1,16 @@
+const std = @import("std");
+const aoc = @import("aoc");
+
+fn part1(allocator: *std.mem.Allocator, input: []u8, args: [][]u8) !void {
+ var answer: u32 = 0;
+
+ std.debug.print("{}\n", .{answer});
+}
+
+fn part2(allocator: *std.mem.Allocator, input: []u8, args: [][]u8) !void {
+ var answer: u32 = 0;
+
+ std.debug.print("{}\n", .{answer});
+}
+
+pub const main = aoc.gen_main(part1, part2);
