Day 5

src/day5/main.rs

@@ -0,0 +1,84 @@
+use anyhow::Result;
+use std::{fs, ops::RangeInclusive};
+
+trait Extend<T> {
+    fn extend(&self, other: &T) -> Option<T>;
+}
+
+impl Extend<RangeInclusive<u64>> for RangeInclusive<u64> {
+    fn extend(&self, other: &RangeInclusive<u64>) -> Option<RangeInclusive<u64>> {
+        if other.contains(self.start()) && other.contains(self.end()) {
+            return Some(other.clone());
+        } else if self.contains(other.start()) && self.contains(other.end()) {
+            return Some((*self).clone());
+        } else if self.contains(other.start()) {
+            return Some(*self.start()..=*other.end());
+        } else if self.contains(other.end()) {
+            return Some(*other.start()..=*self.end());
+        }
+        return None;
+    }
+}
+
+fn main() -> Result<()> {
+    let text = fs::read_to_string("src/day5/act.txt")?;
+
+    let mut valid_ids: Vec<Option<RangeInclusive<u64>>> = text
+        .split("\n")
+        .take_while(|s| s.len() > 0)
+        .map(|s| {
+            let mut v = s.split('-').map(|a| a.parse().unwrap());
+            let start: u64 = v.next().unwrap();
+            let end: u64 = v.next().unwrap();
+            return Some(start..=end);
+        })
+        .collect();
+
+    let mut expanded = true;
+    while expanded {
+        expanded = false;
+        for i in 0..valid_ids.len() {
+            let range_to_extend = &valid_ids[i];
+            if range_to_extend.is_some() {
+                let mut range_to_extend = valid_ids[i].as_ref().unwrap().clone();
+                for j in (i + 1)..valid_ids.len() {
+                    if let Some(maybe_comp) = valid_ids[j].as_ref() {
+                        if let Some(extended) = range_to_extend.extend(&maybe_comp) {
+                            println!(
+                                "{:?} expanded by {:?} into {:?}",
+                                range_to_extend, maybe_comp, extended
+                            );
+                            expanded = true;
+                            range_to_extend = extended;
+                            valid_ids[j] = None;
+                        }
+                    }
+                }
+                valid_ids[i] = Some(range_to_extend);
+            }
+        }
+        valid_ids = valid_ids.into_iter().filter(|a| a.is_some()).collect();
+    }
+
+    let valid_ids = valid_ids.into_iter().map(|a| a.unwrap());
+
+    valid_ids.clone().for_each(|a| println!("{:?}", a));
+
+    let ids_to_check = text
+        .split("\n")
+        .skip_while(|s| s.len() > 0)
+        .skip(1)
+        .filter(|s| s.len() > 0)
+        .fold(0, |sum, line| {
+            let i: u64 = line.parse().unwrap();
+            sum + valid_ids.clone().any(|range| range.contains(&i)) as i64
+        });
+
+    let num_valid_ids = valid_ids.fold(0, |sum, range_id| {
+        sum + range_id.end() - range_id.start() + 1
+    });
+
+    println!("sol1: {}! sol2: {}", ids_to_check, num_valid_ids);
+
+    Ok(())
+}

src/day5/test.txt

@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32