Added 2022 day 4

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) <year> <copyright holders>
+Copyright (c) 2022 niku
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

aoc2022/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "aoc2022"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

aoc2022/src/day_4.rs

@@ -0,0 +1,78 @@
+#[derive(Debug)]
+struct Range(i32, i32);
+
+impl Range {
+    fn contains(&self, other: &Range) -> bool {
+        return self.0 <= other.0 && self.1 >= other.1;
+    }
+
+    fn from_str(string: &str) -> Range {
+        let (start, end) = string.split_once('-').unwrap();
+        return Range(start.parse::<i32>().unwrap(), end.parse::<i32>().unwrap());
+    }
+}
+
+fn parse_pairs(line: &str) -> (Range, Range) {
+    let (left, right) = line.split_once(',').unwrap();
+    return (Range::from_str(left), Range::from_str(right));
+}
+
+fn solution_part1(input: &str) -> i32 {
+    let mut result: i32 = 0;
+    for line in input.lines() {
+        let (left, right) = parse_pairs(line);
+        if left.contains(&right) || right.contains(&left) {
+            result += 1;
+        }
+    }
+    return result;
+}
+
+fn solution_part2(input: &str) -> i32 {
+    let mut result: i32 = 0;
+    for line in input.lines() {
+        let (left, right) = parse_pairs(line);
+        if left.0 <= right.1 && left.1 >= right.0 {
+            result += 1;
+        }
+    }
+    return result;
+}
+
+#[cfg(test)]
+mod tests {
+    use std::fs;
+
+    use super::*;
+
+    #[test]
+    fn contains() {
+        assert!(Range(4, 6).contains(&Range(6, 6)))
+    }
+
+    #[test]
+    fn basic_example() {
+        let input = "2-4,6-8\n2-3,4-5\n5-7,7-9\n2-8,3-7\n6-6,4-6\n2-6,4-8";
+        let expected = 2;
+        let result = solution_part1(input);
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn answer_part1() {
+        let input = fs::read_to_string("inputs/day_4.txt").unwrap();
+        println!(
+            "Answer to part 1 of day 4: {:#?}",
+            solution_part1(input.as_str())
+        );
+    }
+
+    #[test]
+    fn answer_part2() {
+        let input = fs::read_to_string("inputs/day_4.txt").unwrap();
+        println!(
+            "Answer to part 2 of day 4: {:#?}",
+            solution_part2(input.as_str())
+        );
+    }
+}

aoc2022/src/lib.rs

@@ -0,0 +1,2 @@
+#[allow(dead_code)]
+mod day_4;