Add code generator for 2021 and update README

README.md

@@ -1,3 +1,56 @@
 # Advent of Code 2021
 
-The 2021 iteration of Advent of Code. This year I am going to try and accomplish it all on my iPad using GitPod
+The 2021 iteration of Advent of Code. This year I am going to try and accomplish it all on my iPad using GitPod
+
+## Adding a new day
+
+When starting to solve for a new day run the following command in the root of the repo where `<day>` is the go lang compatible package name (i.e. `four` or `five`) and `<noun>` represents the item the day's problem revolves around (i.e. `radar` or `bingo`).
+
+```sh
+./setup.sh <day> <noun>
+```
+
+After generating a new package update [`main.go`](main.go) to include a `<day>` flag in the switch statement on line 28
+
+```go
+  case "<day>":
+		day = <day>.Init("<day>/input.txt")
+```
+
+## My Solutions
+
+### Day 1
+
+```sh
+$ ./aoc2021 --one
+The solution for "one" is:
+There were 1715 increases in depth
+There were 1739 increases in depth when sampling a window
+```
+
+### Day 2
+
+```sh 
+$ ./aoc2021 --two
+The solution for "two" is:
+Horizontal is 1832, depth is 1172, answer is 2147104
+Horizontal is 1832, depth is 1116059, answer is 2044620088
+```
+
+### Day 3
+
+```sh
+$ ./aoc2021 --three
+The solution for "three" is:
+The power rates are gamma: 1143, epsilon: 2952, for 3374136 total
+The oxygen rating is 1909 and CO2 rating is 2322, for a life support rating of 4432698
+```
+
+### Day 4
+
+```sh
+$ ./aoc2021 --four
+The solution for "four" is:
+The winning score is 668 on call 66. Final score 44088
+The last winning score is 263 on call 90. Final score 23670
+```

setup.sh

@@ -0,0 +1,93 @@
+#!/bin/bash
+
+mkdir $1
+
+name=$(echo $1 | awk '{print toupper(substr($0,1,1)) tolower(substr($0,2)) }')
+abbr=$(echo $2 | awk '{print substr($0,1,1) }')
+
+# Create day implementation
+echo "package $1
+
+type $name struct {
+	$2 $2
+}
+
+func Init(filepath string) *$name {
+	$1 := &$name{
+		$2: $2{},
+	}
+
+	$1.$2.load(filepath)
+	return $1
+}
+
+func (d *$name) Answer() string {
+	return \"$1 part 1 answer for $2\"
+}
+
+func (d *$name) FollowUp() string {
+	return \"$1 part 2 answer for $2\"
+}
+" >> $1/main.go
+
+# Create file for the day
+echo "package $1
+import (
+	\"bufio\"
+	\"os\"
+)
+
+type $2 struct {
+  input []string
+}
+
+func ($abbr *$2) load(filename string) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+    $abbr.input = append($abbr.input, scanner.Text())
+	}
+	return nil
+}
+" >> $1/$2.go
+
+# Create the test file
+echo "package $1
+
+import \"testing\"
+
+func Test_read(t *testing.T) {
+	$abbr := $2{}
+	if err := $abbr.load(\"test_input.txt\"); err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+
+	if len($abbr.input) != 1000 {
+		t.Logf(\"Expected 1000 inputs, found %d\", len($abbr.input))
+		t.Fail()
+	}
+
+}
+" >> $1/$2_test.go
+
+# Create files for test input
+touch $1/test_input.txt
+touch $1/input.txt
+
+# Append Solution to Readme
+
+echo "
+### Day $1
+
+\`\`\`sh
+$ ./aoc2021 --$1
+The solution for \"$1\" is:
+$1 part 1 answer for $2
+$1 part 2 answer for $2
+\`\`\`
+" >> README.md