Minor simplification to 2021day01

1 files changed, 2 insertions, 6 deletions

diff --git a/2021/rust/day01/src/main.rs b/2021/rust/day01/src/main.rs
index 559f98c..d0ac932 100644
--- a/2021/rust/day01/src/main.rs
+++ b/2021/rust/day01/src/main.rs
@@ -32,7 +32,7 @@ enum Change {
 }
 
 fn count_increases<'a, I: IntoIterator<Item = &'a usize>>(values: I) -> usize {
-    let changes: Vec<Change> = values.into_iter().scan(None, |state, val| {
+    values.into_iter().scan(None, |state, val| {
         let next = match state {
             None => Change::NoPrevVal,
             Some(prev) if val < *prev => Change::Decreased,
@@ -42,11 +42,7 @@ fn count_increases<'a, I: IntoIterator<Item = &'a usize>>(values: I) -> usize {
         };
         *state = Some(val);
         Some(next)
-    }).collect();
-
-    changes.iter().fold(0, |count, change|
-        if *change == Change::Increased { count + 1 } else { count }
-    )
+    }).filter(|change| change == &Change::Increased).count()
 }
 
 fn part1<'a, I: IntoIterator<Item = &'a usize>>(input: I) -> Result<usize> {