Clarified repository license

README.md

@@ -2,3 +2,6 @@
 This repo contains the result of a masochistic chemical engineer.
 
 https://adventofcode.com/
+
+### License
+This repository is licensed under the MIT license unless otherwise specified.

day4/README.md

@@ -19,3 +19,11 @@ Part 2 is written in Go and can only be ran on Linux, so it counts.
 #### Part 2:
 0. (Optional) Compile `d4p2.go`
 1. Run the program specifying the input as the first command line argument. `go run d4p2.go input` or `./d4p2 input`
+
+### FAQ:
+#### 1. Spreadsheets aren't a programming language!!!!!!!!!!!!!!!!!!
+That's not a question.
+#### 2. Aren't you cheating by not using a non-programming language such as a spreadsheet?
+Don't care.
+
+(Besides, it was harder this way)

day4/d4p2.go

@@ -1,4 +1,3 @@
-// +build linux
 package main
 
 import (
@@ -8,6 +7,7 @@ import (
     "os"
     "strings"
     "regexp"
+    "runtime"
 )
 
 func find_num_wins(winners string, numbers string) int {
@@ -24,6 +24,10 @@ func find_num_wins(winners string, numbers string) int {
 
 
 func main() {
+    if runtime.GOOS != "linux" {
+        panic("This is for Linux only.")
+    }
+
     if len(os.Args) < 2 {
         panic("You did not specify an input file.")
     }