Improvments

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "peak-and-valley"
-author = "Fistons <eric@pedr0.net>"
+authors = ["Fistons <eric@pedr0.net>"]
 version = "0.1.0"
 edition = "2024"
 

src/main.rs

@@ -1,17 +1,12 @@
 #[allow(dead_code)]
 fn find_peaks_and_valleys(values: &[isize]) -> Vec<usize> {
     values
-        .windows(3)
-        .enumerate()
-        .flat_map(|(idx, arr)| {
-            let (a, b, c) = (arr[0], arr[1], arr[2]);
-            if (b > a && b > c) || (b < a && b < c) {
-                Some(idx + 1)
-            } else {
-                None
-            }
-        })
-        .collect()
+        .windows(3) // Take three consecutives elements at once
+        .enumerate() // Get the index of the first one
+        .map(|(idx, arr)| (idx, [arr[0], arr[1], arr[2]])) // Map the elements as a fixed size array
+        .filter(|(_, [a, b, c])| (b > a && b > c) || (b < a && b < c)) // Keep if the middle element is peak or valley
+        .map(|(idx, _)| idx + 1) // Map to index of the middle element
+        .collect() // Profit!
 }
 
 fn main() {}