Solve Part 1

src/main.rs

@@ -1,3 +1,39 @@
-fn main() {
+// https://adventofcode.com/2022/day/4
-    println!("Hello, world!");
+
+use std::ops::Range;
+
+const DATA: &'static str = include_str!("input.txt");
+
+fn parse_range(string: &str) -> Range<i32>
+{
+    let (left, right) = string.split_once("-").unwrap();
+
+    left.parse().unwrap() .. right.parse().unwrap()
+}
+
+fn part1()
+{
+    let mut pairs_fully_contained = 0;
+    for slice in DATA.split("\n")
+    {
+        if slice.is_empty() { continue; }
+
+        let (left, right) = slice.split_once(",").expect("Input data is not correctly structured");
+
+        let left_range = parse_range(left);
+        let right_range = parse_range(right);
+
+        if left_range.end >= right_range.end && left_range.start <= right_range.start
+        {
+            pairs_fully_contained += 1;
+        } else if right_range.end >= left_range.end && right_range.start <= left_range.start
+        {
+            pairs_fully_contained += 1;
+        }
+    }
+    println!("There are {} pairs in which one range is fully contained in the other one", pairs_fully_contained);
+}
+
+fn main() {
+    part1()
 }