From 4c04db23f461337e26bfacbd8e285708b1c2c90e Mon Sep 17 00:00:00 2001
From: Inga <inga-lovinde@noreply.oomza.cutegay.software>
Date: Fri, 1 Dec 2023 22:15:41 +0000
Subject: [PATCH] day 1, part 1

---
 .gitignore              |  3 ++
 README.md               |  1 +
 day01-easy/build.zig    | 70 +++++++++++++++++++++++++++++++++++++++++
 day01-easy/sample.in    |  4 +++
 day01-easy/src/main.zig | 37 ++++++++++++++++++++++
 5 files changed, 115 insertions(+)
 create mode 100644 day01-easy/build.zig
 create mode 100644 day01-easy/sample.in
 create mode 100644 day01-easy/src/main.zig

diff --git a/.gitignore b/.gitignore
index feda423..374ef15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,6 @@ zig-out/
 /build/
 /build-*/
 /docgen_tmp/
+
+easy.in
+hard.in
diff --git a/README.md b/README.md
index 1c5765f..ad8cf20 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,3 @@
 # AdventOfCode-2023
 
+Solutions to https://adventofcode.com/2023/
\ No newline at end of file
diff --git a/day01-easy/build.zig b/day01-easy/build.zig
new file mode 100644
index 0000000..86d7cb6
--- /dev/null
+++ b/day01-easy/build.zig
@@ -0,0 +1,70 @@
+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 = "day01-easy",
+        // In this case the main source file is merely a path, however, in more
+        // complicated build scripts, this could be a generated file.
+        .root_source_file = .{ .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);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const unit_tests = b.addTest(.{
+        .root_source_file = .{ .path = "src/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_unit_tests = b.addRunArtifact(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_unit_tests.step);
+}
diff --git a/day01-easy/sample.in b/day01-easy/sample.in
new file mode 100644
index 0000000..1ba8437
--- /dev/null
+++ b/day01-easy/sample.in
@@ -0,0 +1,4 @@
+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet
\ No newline at end of file
diff --git a/day01-easy/src/main.zig b/day01-easy/src/main.zig
new file mode 100644
index 0000000..1d2b2fc
--- /dev/null
+++ b/day01-easy/src/main.zig
@@ -0,0 +1,37 @@
+const std = @import("std");
+
+pub fn main() !void {
+    const stdout = std.io.getStdOut().writer();
+
+    const raw_in = std.io.getStdIn();
+    var buffered_reader = std.io.bufferedReader(raw_in.reader());
+    var reader = buffered_reader.reader();
+
+    var result: u32 = 0;
+    var line_buffer: [1000]u8 = undefined;
+    while (try reader.readUntilDelimiterOrEof(&line_buffer, '\n')) |line| {
+        var firstDigit: u8 = 0;
+        var lastDigit: u8 = 0;
+        for (0..line.len) |i| {
+            const char = line[i];
+            if (char >= '0' and char <= '9') {
+                firstDigit = char - '0';
+                break;
+            }
+        }
+        for (0..line.len) |i| {
+            const index = line.len - i - 1;
+            const char = line[index];
+            if (char >= '0' and char <= '9') {
+                lastDigit = char - '0';
+                break;
+            }
+        }
+
+        result += firstDigit * 10 + lastDigit;
+    }
+    try stdout.print(
+        "{d}\n",
+        .{result},
+    );
+}