From 894ddd8ca759bf8fbb07608108cb3dc40f853c9c Mon Sep 17 00:00:00 2001
From: David Ashby <delta.mu.alpha@gmail.com>
Date: Sat, 3 Dec 2022 09:04:06 -0500
Subject: [PATCH] clean up part 2 a bit

---
 03/main.rs | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/03/main.rs b/03/main.rs
index 77d6b8b..7d1c1bb 100644
--- a/03/main.rs
+++ b/03/main.rs
@@ -1,10 +1,10 @@
 #![allow(dead_code)]
-use std::collections::hash_map::RandomState;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::fs::File;
 use std::io;
 use std::io::BufRead;
+use std::iter::FromIterator;
 use std::path::Path;
 use std::time::Instant;
 
@@ -64,10 +64,7 @@ fn part_two() {
         for line in lines {
             if let Ok(contents) = line {
                 // build the group
-                let mut knapsack = HashSet::new();
-                for item in contents.chars() {
-                    knapsack.insert(item);
-                }
+                let knapsack = HashSet::from_iter(contents.chars());
                 group.push(knapsack);
                 if group.len() != 3 {
                     continue;
@@ -75,14 +72,13 @@ fn part_two() {
                 if let (Some(one), Some(two), Some(three)) =
                     (group.get(0), group.get(1), group.get(2))
                 {
-                    let intermediate_one: _ = two
-                        .intersection(three)
-                        .collect::<HashSet<&char, RandomState>>();
-                    let intermediate_two: _ = one
-                        .intersection(three)
-                        .collect::<HashSet<&char, RandomState>>();
+                    let intermediate_one: HashSet<&char> =
+                        HashSet::from_iter(two.intersection(three));
+                    let intermediate_two: HashSet<&char> =
+                        HashSet::from_iter(one.intersection(three));
                     let mut result = intermediate_one.intersection(&intermediate_two);
                     if let Some(item) = result.next() {
+                        // double pointers!
                         if **item as u32 > 96 {
                             priorities += **item as u32 - 96
                         } else {