Update Binary Search algorithm

soul-catcher · soul-catcher · commit c7b479dc5aba · 2021-01-24T00:35:23.000+07:00
diff --git a/src/searching/binary_search.rs b/src/searching/binary_search.rs
@@ -1,31 +1,19 @@
-use std::cmp::{PartialEq, PartialOrd};
-
-pub fn binary_search<T: PartialEq + PartialOrd>(item: &T, arr: &[T]) -> Option<usize> {
-    if arr.is_empty() {
-        return None;
-    }
+use std::cmp::Ordering;
 
+pub fn binary_search<T: Ord>(item: &T, arr: &[T]) -> Option<usize> {
     let mut left = 0;
-    let mut right = arr.len() - 1;
+    let mut right = arr.len();
 
     while left < right {
-        let mid = left + (right - left) / 2;
+        let mid = (left + right) / 2;
 
-        if &arr[mid] > item {
-            right = mid - 1;
-        } else if &arr[mid] < item {
-            left = mid + 1;
-        } else {
-            left = mid;
-            break;
+        match item.cmp(&arr[mid]) {
+            Ordering::Less => right = mid,
+            Ordering::Equal => return Some(mid),
+            Ordering::Greater => left = mid + 1,
         }
     }
-
-    if &arr[left] == item {
-        Some(left)
-    } else {
-        None
-    }
+    None
 }
 
 #[cfg(test)]
