From c807045e22ae3869b61e4d730dfb98c0addc1a24 Mon Sep 17 00:00:00 2001 From: Lucia Ceionia Date: Wed, 4 Dec 2024 00:22:36 -0600 Subject: [PATCH] day 4 --- 04/build.zig | 66 +++++++++++++++++++++++ 04/build.zig.zon | 72 +++++++++++++++++++++++++ 04/src/main.zig | 133 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 271 insertions(+) create mode 100644 04/build.zig create mode 100644 04/build.zig.zon create mode 100644 04/src/main.zig diff --git a/04/build.zig b/04/build.zig new file mode 100644 index 0000000..567d604 --- /dev/null +++ b/04/build.zig @@ -0,0 +1,66 @@ +const std = @import("std"); + +// Although this function looks imperative, note that its job is to +// declaratively construct a build graph that will be executed by an external +// runner. +pub fn build(b: *std.Build) void { + // Standard target options allows the person running `zig build` to choose + // what target to build for. Here we do not override the defaults, which + // means any target is allowed, and the default is native. Other options + // for restricting supported target set are available. + const target = b.standardTargetOptions(.{}); + + // Standard optimization options allow the person running `zig build` to select + // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not + // set a preferred release mode, allowing the user to decide how to optimize. + const optimize = b.standardOptimizeOption(.{}); + + const exe = b.addExecutable(.{ + .name = "04", + .root_source_file = b.path("src/main.zig"), + .target = target, + .optimize = optimize, + }); + + // This declares intent for the executable to be installed into the + // standard location when the user invokes the "install" step (the default + // step when running `zig build`). + b.installArtifact(exe); + + // This *creates* a Run step in the build graph, to be executed when another + // step is evaluated that depends on it. The next line below will establish + // such a dependency. + const run_cmd = b.addRunArtifact(exe); + + // By making the run step depend on the install step, it will be run from the + // installation directory rather than directly from within the cache directory. + // This is not necessary, however, if the application depends on other installed + // files, this ensures they will be present and in the expected location. + run_cmd.step.dependOn(b.getInstallStep()); + + // This allows the user to pass arguments to the application in the build + // command itself, like this: `zig build run -- arg1 arg2 etc` + if (b.args) |args| { + run_cmd.addArgs(args); + } + + // This creates a build step. It will be visible in the `zig build --help` menu, + // and can be selected like this: `zig build run` + // This will evaluate the `run` step rather than the default, which is "install". + const run_step = b.step("run", "Run the app"); + run_step.dependOn(&run_cmd.step); + + const exe_unit_tests = b.addTest(.{ + .root_source_file = b.path("src/main.zig"), + .target = target, + .optimize = optimize, + }); + + const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests); + + // Similar to creating the run step earlier, this exposes a `test` step to + // the `zig build --help` menu, providing a way for the user to request + // running the unit tests. + const test_step = b.step("test", "Run unit tests"); + test_step.dependOn(&run_exe_unit_tests.step); +} diff --git a/04/build.zig.zon b/04/build.zig.zon new file mode 100644 index 0000000..96aa0bb --- /dev/null +++ b/04/build.zig.zon @@ -0,0 +1,72 @@ +.{ + // This is the default name used by packages depending on this one. For + // example, when a user runs `zig fetch --save `, this field is used + // as the key in the `dependencies` table. Although the user can choose a + // different name, most users will stick with this provided value. + // + // It is redundant to include "zig" in this name because it is already + // within the Zig package namespace. + .name = "04", + + // This is a [Semantic Version](https://semver.org/). + // In a future version of Zig it will be used for package deduplication. + .version = "0.0.0", + + // This field is optional. + // This is currently advisory only; Zig does not yet do anything + // with this value. + //.minimum_zig_version = "0.11.0", + + // This field is optional. + // Each dependency must either provide a `url` and `hash`, or a `path`. + // `zig build --fetch` can be used to fetch all dependencies of a package, recursively. + // Once all dependencies are fetched, `zig build` no longer requires + // internet connectivity. + .dependencies = .{ + // See `zig fetch --save ` for a command-line interface for adding dependencies. + //.example = .{ + // // When updating this field to a new URL, be sure to delete the corresponding + // // `hash`, otherwise you are communicating that you expect to find the old hash at + // // the new URL. + // .url = "https://example.com/foo.tar.gz", + // + // // This is computed from the file contents of the directory of files that is + // // obtained after fetching `url` and applying the inclusion rules given by + // // `paths`. + // // + // // This field is the source of truth; packages do not come from a `url`; they + // // come from a `hash`. `url` is just one of many possible mirrors for how to + // // obtain a package matching this `hash`. + // // + // // Uses the [multihash](https://multiformats.io/multihash/) format. + // .hash = "...", + // + // // When this is provided, the package is found in a directory relative to the + // // build root. In this case the package's hash is irrelevant and therefore not + // // computed. This field and `url` are mutually exclusive. + // .path = "foo", + + // // When this is set to `true`, a package is declared to be lazily + // // fetched. This makes the dependency only get fetched if it is + // // actually used. + // .lazy = false, + //}, + }, + + // Specifies the set of files and directories that are included in this package. + // Only files and directories listed here are included in the `hash` that + // is computed for this package. Only files listed here will remain on disk + // when using the zig package manager. As a rule of thumb, one should list + // files required for compilation plus any license(s). + // Paths are relative to the build root. Use the empty string (`""`) to refer to + // the build root itself. + // A directory listed here means that all files within, recursively, are included. + .paths = .{ + "build.zig", + "build.zig.zon", + "src", + // For example... + //"LICENSE", + //"README.md", + }, +} diff --git a/04/src/main.zig b/04/src/main.zig new file mode 100644 index 0000000..e1e3b79 --- /dev/null +++ b/04/src/main.zig @@ -0,0 +1,133 @@ +// @intCast(). what the fuck. why. +// still feels like i'm fighting the language. +// but not as bad as yesterday. + +const std = @import("std"); + +var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator); +const alloc = arena.allocator(); + +const test_data = @embedFile("test"); +const input_data = @embedFile("input"); + +pub fn main() !void { + const stdout = std.io.getStdOut().writer(); + + const value1 = try run1(input_data); + try stdout.print("{d}\n", .{value1}); + + const value2 = try run2(input_data); + try stdout.print("{d}\n", .{value2}); +} + +test "test input part 1" { + std.debug.print("\n", .{}); + const value = try run1(test_data); + std.debug.print("{d}\n", .{value}); + try std.testing.expectEqual(18, value); +} + +test "test input part 2" { + std.debug.print("\n",.{}); + const value = try run2(test_data); + std.debug.print("{d}\n", .{value}); + try std.testing.expectEqual(9, value); +} + +fn parseIntFromReader(reader: anytype) anyerror!u64 { + const f = try reader.readByte(); + if (f < '0' or f > '9') return error.BadCharacter; + var v: u64 = f - '0'; + while (true) { + const c = try reader.readByte(); + if (c < '0' or c > '9') { + break; + } else { + v = (v * 10) + (c - '0'); + } + } + return v; +} + +fn run2(s: []const u8) !u64 { + var map: [256][256]u8 = [_][256]u8{[_]u8{0}**256}**256; + var lines = std.mem.splitScalar(u8, s, '\n'); + + const PAD = 8; + + var y: isize = PAD; + while (lines.next()) |line| { + if (std.mem.eql(u8, line, "")) continue; + std.mem.copyForwards(u8, map[@intCast(y)][PAD..], line); + y += 1; + } + + var total: u64 = 0; + + y = PAD; + while (y < 256) : (y += 1) { + if (map[@intCast(y)][PAD] == 0) continue; + + var x: isize = PAD; + while (x < 256) : (x += 1) { + if (map[@intCast(y)][@intCast(x)] == 'A') { + const x1 = + (map[@intCast(y-1)][@intCast(x-1)] == 'M' + and map[@intCast(y+1)][@intCast(x+1)] == 'S') + or + (map[@intCast(y-1)][@intCast(x-1)] == 'S' + and map[@intCast(y+1)][@intCast(x+1)] == 'M'); + const x2 = + (map[@intCast(y-1)][@intCast(x+1)] == 'M' + and map[@intCast(y+1)][@intCast(x-1)] == 'S') + or + (map[@intCast(y-1)][@intCast(x+1)] == 'S' + and map[@intCast(y+1)][@intCast(x-1)] == 'M'); + if (x1 and x2) total += 1; + } + } + } + + return total; +} + +fn run1(s: []const u8) !u64 { + var map: [256][256]u8 = [_][256]u8{[_]u8{0}**256}**256; + var lines = std.mem.splitScalar(u8, s, '\n'); + + const PAD = 8; + + var y: isize = PAD; + while (lines.next()) |line| { + if (std.mem.eql(u8, line, "")) continue; + std.mem.copyForwards(u8, map[@intCast(y)][PAD..], line); + y += 1; + } + + var total: u64 = 0; + + y = PAD; + const dirs: [9][2]isize = .{ + .{-1,0}, .{-1,1}, .{-1,-1}, + .{ 0,0}, .{ 0,1}, .{ 0,-1}, + .{ 1,0}, .{ 1,1}, .{ 1,-1}, + }; + while (y < 256) : (y += 1) { + if (map[@intCast(y)][PAD] == 0) continue; + + var x: isize = PAD; + while (x < 256) : (x += 1) { + if (map[@intCast(y)][@intCast(x)] == 'X') { + for (dirs) |dir| { + const xmintCast = + map[@intCast(y + dir[0]*1)][@intCast(x + dir[1]*1)] == 'M' and + map[@intCast(y + dir[0]*2)][@intCast(x + dir[1]*2)] == 'A' and + map[@intCast(y + dir[0]*3)][@intCast(x + dir[1]*3)] == 'S'; + if (xmintCast) total += 1; + } + } + } + } + + return total; +}