some formatting and some optimizations

day1/src/main.rs

@@ -1,25 +1,22 @@
 use std::fs::File;
 use std::io::{prelude::*, BufReader};
 
-fn main() -> std::io::Result<()>{
+fn main() -> std::io::Result<()> {
     let file = File::open("input")?;
     let reader = BufReader::new(file);
 
-    let mut elves = reader.lines()
-        .fold(Vec::new(), |mut acc, line| {
-            let line = line.unwrap();
-            //empty lines mean new elf
-            if line.is_empty() || acc.is_empty() {
-                acc.push(0_u64);
-            }
-
+    let mut elves = reader.lines().fold(vec![0_u64], |mut acc, line| {
+        let line = line.unwrap();
+        //empty lines mean new elf
+        if line.is_empty() {
+            acc.push(0_u64);
+        } else {
             // the first time through is an edge case preventing an else here
-            if ! line.is_empty() {
-                let last = acc.last_mut().unwrap();
-                *last += line.parse::<u64>().unwrap();
-            }
-            acc
-        });
+            let last = acc.last_mut().unwrap();
+            *last += line.parse::<u64>().unwrap();
+        }
+        acc
+    });
 
     //order the elves since we don't care about position anymore
     elves.sort();
@@ -29,7 +26,7 @@ fn main() -> std::io::Result<()>{
     println!("Part 1: {}", elves[max]);
 
     //Part 2 is get the sum of the largest 3
-    let counts: u64 = elves[(max-2)..].iter().sum();
+    let counts: u64 = elves[(max - 2)..].iter().sum();
     println!("Part 2: {counts}");
 
     Ok(())

day2/src/main.rs

@@ -2,10 +2,10 @@ use std::fs::File;
 use std::io::{prelude::*, BufReader};
 
 #[derive(Debug)]
-struct HoHoError{}
+struct HoHoError {}
 
 #[derive(PartialEq)]
-enum Choice{
+enum Choice {
     Rock = 1,
     Paper,
     Scissors,
@@ -18,7 +18,7 @@ impl std::str::FromStr for Choice {
             "A" | "X" => Ok(Choice::Rock),
             "B" | "Y" => Ok(Choice::Paper),
             "C" | "Z" => Ok(Choice::Scissors),
-            _ => Err(HoHoError{}),
+            _ => Err(HoHoError {}),
         }
     }
 }
@@ -33,7 +33,7 @@ impl Choice {
         }
         0
     }
-    fn beats (&self) -> Choice {
+    fn beats(&self) -> Choice {
         match self {
             Choice::Rock => Choice::Scissors,
             Choice::Paper => Choice::Rock,
@@ -49,7 +49,7 @@ impl Choice {
     }
 }
 
-struct Game{
+struct Game {
     pub opponent: Choice,
     pub you: Choice,
 }
@@ -57,7 +57,7 @@ struct Game{
 impl std::str::FromStr for Game {
     type Err = HoHoError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let str_split = s.split(" ").collect::<Vec<&str>>();
+        let str_split = s.split(' ').collect::<Vec<&str>>();
         let opponent: Choice = str_split[0].parse()?;
         // game1
         //let you: Choice = str_split[1].parse()?;
@@ -65,14 +65,14 @@ impl std::str::FromStr for Game {
             "X" => opponent.beats(),
             "Y" => str_split[0].parse()?,
             "Z" => opponent.loses(),
-            _ => return Err(HoHoError{})
+            _ => return Err(HoHoError {}),
         };
-        Ok(Game{opponent, you})
+        Ok(Game { opponent, you })
     }
 }
 
 impl Game {
-    fn outcome (&self) -> i32 {
+    fn outcome(&self) -> i32 {
         self.you.cmp(&self.opponent)
     }
 
@@ -82,7 +82,7 @@ impl Game {
     }
 }
 
-fn main() -> std::io::Result<()>{
+fn main() -> std::io::Result<()> {
     //read in file
     let file = File::open("input")?;
     let reader = BufReader::new(file);

day3/src/main.rs

@@ -7,24 +7,25 @@ fn main() -> std::io::Result<()> {
     let reader = BufReader::new(file);
 
     /*
-    let value = reader
-        .lines()
-        .map(|line| {
-            let line = line.unwrap();
-            let (comp1, comp2) = line.split_at(line.len() / 2);
-            let duplicate = comp2.chars().find(|c| comp1.contains(*c)).unwrap();
-            match duplicate {
-                n @'a'..='z' => (n as i32) - ('a' as i32) + 1_i32,
-                n @ 'A'..='Z' => (n as i32) - ('A' as i32) + 27_i32,
-                _ => 0,
-            }
-        })
-        .sum::<i32>();
-    println!("Part 1: {value}");
-*/
+        let value = reader
+            .lines()
+            .map(|line| {
+                let line = line.unwrap();
+                let (comp1, comp2) = line.split_at(line.len() / 2);
+                let duplicate = comp2.chars().find(|c| comp1.contains(*c)).unwrap();
+                match duplicate {
+                    n @'a'..='z' => (n as i32) - ('a' as i32) + 1_i32,
+                    n @ 'A'..='Z' => (n as i32) - ('A' as i32) + 27_i32,
+                    _ => 0,
+                }
+            })
+            .sum::<i32>();
+        println!("Part 1: {value}");
+    */
     //part 2
     // fold the lines into groups of three
-    let value = reader.lines()
+    let value = reader
+        .lines()
         .fold(Vec::new(), |mut acc: Vec<Vec<String>>, line| {
             if acc.is_empty() || acc.last().unwrap().len() == 3 {
                 acc.push(Vec::new())
@@ -38,7 +39,8 @@ fn main() -> std::io::Result<()> {
                 [g1, g2, g3] => (g1, g2, g3),
                 _ => panic!("not get here"),
             };
-            match g1.chars() 
+            match g1
+                .chars()
                 .fold(Vec::new(), |mut combo: Vec<char>, ch| {
                     if g2.contains(ch) {
                         combo.push(ch)
@@ -46,14 +48,15 @@ fn main() -> std::io::Result<()> {
                     combo
                 })
                 .iter()
-                .find(|c| {
-                    g3.contains(**c)
-                }).unwrap(){
+                .find(|c| g3.contains(**c))
+                .unwrap()
+            {
                 n @ 'a'..='z' => (*n as i32) - ('a' as i32) + 1_i32,
                 n @ 'A'..='Z' => (*n as i32) - ('A' as i32) + 27_i32,
                 _ => 0,
             }
-        }).sum::<i32>();
+        })
+        .sum::<i32>();
     println!("Part 2: {value}");
     // find common letter in the groups
     //   find common letters in the first 2 then find the common in the third