Miscellaneous cleanups

Author: ephemient

rs/src/day22.rs

@@ -1,4 +1,4 @@
-use std::iter;
+use std::iter::successors;
 use std::sync::atomic::{AtomicU32, Ordering};
 
 use itertools::Itertools;
@@ -14,7 +14,7 @@ pub fn part1(data: &str) -> u64 {
     data.lines()
         .collect::<Vec<_>>()
         .par_iter()
-        .filter_map(|line| iter::successors(line.parse().ok(), |num| Some(step(*num))).nth(2000))
+        .filter_map(|line| successors(line.parse().ok(), |num| Some(step(*num))).nth(2000))
         .map(Into::<u64>::into)
         .sum()
 }
@@ -26,7 +26,7 @@ pub fn part2(data: &str) -> u32 {
         .par_iter()
         .filter_map(|line| {
             let mut seen = [false; 19 * 19 * 19 * 19];
-            iter::successors(line.parse().ok(), |num| Some(step(*num)))
+            successors(line.parse().ok(), |num| Some(step(*num)))
                 .take(2001)
                 .map(|num| num % 10)
                 .tuple_windows()

rs/src/day8.rs

@@ -1,11 +1,10 @@
 use std::collections::BTreeSet;
-use std::iter::once;
 
 use itertools::Itertools;
 
 fn solve<I>(data: &str, multiples: I) -> usize
 where
-    I: Clone + Iterator<Item = isize>,
+    I: Clone + IntoIterator<Item = isize>,
 {
     let (mut height, mut width) = (0, 0);
     data.lines()
@@ -34,7 +33,7 @@ where
                     .filter(move |point1| point0 != *point1)
                     .flat_map(|(y1, x1)| {
                         let (dy, dx) = (*y1 as isize - *y0 as isize, *x1 as isize - *x0 as isize);
-                        multiples.clone().map_while(move |i| {
+                        multiples.clone().into_iter().map_while(move |i| {
                             Some((
                                 y1.wrapping_add_signed(i * dy),
                                 x1.wrapping_add_signed(i * dx),
@@ -49,7 +48,7 @@ where
 }
 
 pub fn part1(data: &str) -> usize {
-    solve(data, once(1))
+    solve(data, [1])
 }
 
 pub fn part2(data: &str) -> usize {

rs/src/day9.rs

@@ -1,4 +1,4 @@
-use std::cmp::min;
+use std::iter;
 
 fn parse(data: &str) -> Vec<(usize, (u8, u8))> {
     let mut iter = data
@@ -12,7 +12,7 @@ fn parse(data: &str) -> Vec<(usize, (u8, u8))> {
         })
         .chain([0])
         .fuse();
-    std::iter::from_fn(move || iter.next().zip(iter.next()))
+    iter::from_fn(move || iter.next().zip(iter.next()))
         .scan(0, |acc, (used, free)| {
             let offset = *acc;
             *acc += (used + free) as usize;
@@ -38,7 +38,7 @@ pub fn part1(data: &str) -> u64 {
             while free > 0 && id + 1 < *end {
                 let id = *end - 1;
                 let (_, (used2, _)) = data.get_mut(id).unwrap();
-                let moved = min(free, *used2);
+                let moved = free.min(*used2);
                 sum += id as u64 * tri_range(offset as u64, moved as u64);
                 offset += moved as usize;
                 free -= moved;