Generalize a bit

1 files changed, 17 insertions, 4 deletions

diff --git a/src/lib.rs b/src/lib.rs
index eead58f..5f0903a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,10 +1,23 @@
-pub fn brutal(arr: &[usize]) -> Option<usize> {
-    let sum: usize = arr.iter().sum();
+use std::{
+    cmp::PartialEq,
+    iter::Sum,
+    ops::{Add, Sub},
+};
+
+pub fn brutal<T>(arr: &[T]) -> Option<usize>
+where
+    T: for<'a> Sum<&'a T>
+        + for<'a> Sub<&'a T, Output = T>
+        + for<'a> Add<&'a T, Output = T>
+        + PartialEq
+        + Copy,
+{
+    let sum: T = arr.iter().sum();
 
     let x = arr
         .iter()
         .enumerate()
-        .try_fold((0, sum), |(left, right), (idx, x)| {
+        .try_fold((sum - &sum, sum), |(left, right), (idx, x)| {
             if left == right - x {
                 Err(idx)
             } else {
@@ -12,7 +25,7 @@ pub fn brutal(arr: &[usize]) -> Option<usize> {
             }
         });
 
-    if let Err(idx) = x { Some(idx) } else { None }
+    x.err()
 }
 
 #[cfg(test)]