test {
    _ = @import("day01.zig");
}

const std = @import("std");
const fmt = std.fmt;
const fs = std.fs;
const lineLength = 4; // maximum line length (digits)
const decimalSize = u13; // every num in input is < 2^13
const maxItems = 2000; // number of items in input file
const path = "../data/day01/input.txt";
fn first() anyerror!decimalSize {
    const file = @embedFile(path);
    var lines = std.mem.tokenize(u8, file, "\n");
    var values: [maxItems]decimalSize = undefined;
    var i: decimalSize = 0;
    while (lines.next()) |v| : (i += 1) {
        values[i] = try std.fmt.parseUnsigned(decimalSize, v, 10);
    }
    var inc: decimalSize = 0;
    for (values) |v, idx| {
        if (idx == 0) continue;
        if (v > values[idx - 1]) {
            inc += 1;
        }
    }
    return inc;
}
fn second() anyerror!decimalSize {
    const file = @embedFile(path);
    var lines = std.mem.tokenize(u8, file, "\n");
    var values: [maxItems]decimalSize = undefined;
    var i: decimalSize = 0;
    while (lines.next()) |v| : (i += 1) {
        values[i] = try fmt.parseUnsigned(decimalSize, v, 10);
    }
    var inc: decimalSize = 0;
    for (values) |_, idx| {
        if (idx >= 3) {
            const a = @intCast(u15, values[idx - 3]) + values[idx - 2] + values[idx - 1];
            const b = @intCast(u15, values[idx - 2]) + values[idx - 1] + values[idx];
            if (a < b) {
                inc += 1;
            }
        }
    }
    return inc;
}
pub fn main() anyerror!void {
    var timer = try std.time.Timer.start();
    _ = try first();
    const f = timer.lap() / 1000;
    _ = try second();
    const s = timer.read() / 1000;
    std.debug.print("Day 1 \tfirst: {d}μs \tsecond: {d}μs\n", .{ f, s });
}
test "day01a" {
    try std.testing.expectEqual(@as(decimalSize, 1400), try first());
}
test "day01b" {
    try std.testing.expectEqual(@as(decimalSize, 1429), try second());
}

const std = @import("std");
// number of days available
const days = 1;
pub fn build(b: *std.build.Builder) 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 release options allow the person running `zig build` to select
    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
    const mode = b.standardReleaseOptions();
    const run_step = b.step("run", "Run all solver");
    var day: u8 = 1;
    while (day <= days) : (day += 1) {
        const dayString = b.fmt("day{:0>2}", .{day});
        const zigFile = b.fmt("src/{s}.zig", .{dayString});
        const exe = b.addExecutable(dayString, zigFile);
        exe.setTarget(target);
        exe.setBuildMode(mode);
        exe.install();
        const run_cmd = exe.run();
        run_cmd.step.dependOn(b.getInstallStep());
        if (b.args) |args| {
            run_cmd.addArgs(args);
        }
        const run_day = b.step(dayString, "");
        run_day.dependOn(&run_cmd.step);
        // add to main run step too
        run_step.dependOn(&run_cmd.step);
    }
    const exe_tests = b.addTest("src/main.zig");
    exe_tests.setTarget(target);
    exe_tests.setBuildMode(mode);
    const test_step = b.step("test", "Run unit tests");
    test_step.dependOn(&exe_tests.step);
}