Add solution for 2021 day 01

2021/README.md

@@ -1,29 +1,29 @@
 # [Advent of Code 2021](https://adventofcode.com/2021)
 
-## Progress
-
--   [ ] Day 01
--   [ ] Day 02
--   [ ] Day 03
--   [ ] Day 04
--   [ ] Day 05
--   [ ] Day 06
--   [ ] Day 07
--   [ ] Day 08
--   [ ] Day 09
--   [ ] Day 10
--   [ ] Day 11
--   [ ] Day 12
--   [ ] Day 13
--   [ ] Day 14
--   [ ] Day 15
--   [ ] Day 16
--   [ ] Day 17
--   [ ] Day 18
--   [ ] Day 19
--   [ ] Day 20
--   [ ] Day 21
--   [ ] Day 22
--   [ ] Day 23
--   [ ] Day 24
--   [ ] Day 25
+| Solved | Day | Language |
+| :----: | :-: | :------- |
+|   ✓    | 01  | Ruby     |
+|        | 02  |          |
+|        | 03  |          |
+|        | 04  |          |
+|        | 05  |          |
+|        | 06  |          |
+|        | 07  |          |
+|        | 08  |          |
+|        | 09  |          |
+|        | 10  |          |
+|        | 11  |          |
+|        | 12  |          |
+|        | 13  |          |
+|        | 14  |          |
+|        | 15  |          |
+|        | 16  |          |
+|        | 17  |          |
+|        | 18  |          |
+|        | 19  |          |
+|        | 20  |          |
+|        | 21  |          |
+|        | 22  |          |
+|        | 23  |          |
+|        | 24  |          |
+|        | 25  |          |

2021/day-01/inputs/sample.txt

@@ -0,0 +1,10 @@
+199
+200
+208
+210
+200
+207
+240
+269
+260
+263

2021/day-01/part_one.rb

@@ -0,0 +1,13 @@
+#!/usr/bin/env ruby
+
+def part_one(measurements)
+  measurements
+    .each_cons(2)
+    .reduce(0) do |acc, (a, b)|
+      a < b ? acc + 1 : acc
+    end
+end
+
+content = File.readlines(ARGV.first, chomp: true).map(&:to_i)
+result = part_one(content)
+puts(result)

2021/day-01/part_two.rb

@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+
+def part_two(measurements)
+  measurements
+    .each_cons(3)
+    .map { |(x, y, z)| x + y + z }
+    .each_cons(2)
+    .reduce(0) do |acc, (a, b)|
+      a < b ? acc + 1 : acc
+    end
+end
+
+content = File.readlines(ARGV.first, chomp: true).map(&:to_i)
+result = part_two(content)
+puts(result)