diff --git a/hostnames_allocator/tests/ranged_number_allocator_tests.rs b/hostnames_allocator/tests/ranged_number_allocator_tests.rs
index a9045a8..68b177b 100644
--- a/hostnames_allocator/tests/ranged_number_allocator_tests.rs
+++ b/hostnames_allocator/tests/ranged_number_allocator_tests.rs
@@ -2,124 +2,124 @@ extern crate hostnames_allocator;
 
 use hostnames_allocator::ranged_number_allocator::RangedNumberAllocator;
 
-fn create_allocator(data: &[(u32, u32)]) -> RangedNumberAllocator {
+fn create_allocator<const N: usize>(data: [(u32, u32); N]) -> RangedNumberAllocator {
     RangedNumberAllocator {
-        tree: data.to_owned().into_iter().collect()
+        tree: data.into_iter().collect()
     }
 }
 
-fn check_allocator(allocator: RangedNumberAllocator, expected: &[(u32, u32)]) {
-    itertools::assert_equal(allocator.tree, expected.to_owned());
+fn check_allocator<const N: usize>(allocator: RangedNumberAllocator, expected: [(u32, u32); N]) {
+    itertools::assert_equal(allocator.tree, expected);
 }
 
 #[test]
 fn remove_preserves_tree_when_empty() {
-    let mut allocator = create_allocator(&[]);
+    let mut allocator = create_allocator([]);
     allocator.remove(5);
-    check_allocator(allocator, &[]);
+    check_allocator(allocator, []);
 }
 
 #[test]
 fn remove_preserves_tree_when_not_found() {
-    let mut allocator = create_allocator(&[(1, 3), (11, 13)]);
+    let mut allocator = create_allocator([(1, 3), (11, 13)]);
     allocator.remove(5);
-    check_allocator(allocator, &[(1, 3), (11, 13)]);
+    check_allocator(allocator, [(1, 3), (11, 13)]);
 }
 
 #[test]
 fn remove_removes_range_with_single_value() {
-    let mut allocator = create_allocator(&[(1, 3), (5, 5), (11, 13)]);
+    let mut allocator = create_allocator([(1, 3), (5, 5), (11, 13)]);
     allocator.remove(5);
-    check_allocator(allocator, &[(1, 3), (11, 13)]);
+    check_allocator(allocator, [(1, 3), (11, 13)]);
 }
 
 #[test]
 fn remove_replaces_range_starting_with_value() {
-    let mut allocator = create_allocator(&[(1, 3), (5, 7), (11, 13)]);
+    let mut allocator = create_allocator([(1, 3), (5, 7), (11, 13)]);
     allocator.remove(5);
-    check_allocator(allocator, &[(1, 3), (6, 7), (11, 13)]);
+    check_allocator(allocator, [(1, 3), (6, 7), (11, 13)]);
 }
 
 #[test]
 fn remove_changes_range_ending_with_value() {
-    let mut allocator = create_allocator(&[(1, 3), (5, 7), (11, 13)]);
+    let mut allocator = create_allocator([(1, 3), (5, 7), (11, 13)]);
     allocator.remove(7);
-    check_allocator(allocator, &[(1, 3), (5, 6), (11, 13)]);
+    check_allocator(allocator, [(1, 3), (5, 6), (11, 13)]);
 }
 
 #[test]
 fn remove_splits_range_containing_value() {
-    let mut allocator = create_allocator(&[(1, 3), (5, 9), (11, 13)]);
+    let mut allocator = create_allocator([(1, 3), (5, 9), (11, 13)]);
     allocator.remove(7);
-    check_allocator(allocator, &[(1, 3), (5, 6), (8, 9), (11, 13)]);
+    check_allocator(allocator, [(1, 3), (5, 6), (8, 9), (11, 13)]);
 }
 
 #[test]
 fn remove_removes_last_value() {
-    let mut allocator = create_allocator(&[(5, 5)]);
+    let mut allocator = create_allocator([(5, 5)]);
     allocator.remove(5);
-    check_allocator(allocator, &[]);
+    check_allocator(allocator, []);
 }
 
 #[test]
 fn allocate_initializes_empty() {
-    let mut allocator = create_allocator(&[]);
+    let mut allocator = create_allocator([]);
     assert_eq!(allocator.allocate(), 1);
-    check_allocator(allocator, &[(1, 1)]);
+    check_allocator(allocator, [(1, 1)]);
 }
 
 #[test]
 fn allocate_adds_second_value() {
-    let mut allocator = create_allocator(&[(1, 1)]);
+    let mut allocator = create_allocator([(1, 1)]);
     assert_eq!(allocator.allocate(), 2);
-    check_allocator(allocator, &[(1, 2)]);
+    check_allocator(allocator, [(1, 2)]);
 }
 
 #[test]
 fn allocate_adds_tenth_value() {
-    let mut allocator = create_allocator(&[(1, 9)]);
+    let mut allocator = create_allocator([(1, 9)]);
     assert_eq!(allocator.allocate(), 10);
-    check_allocator(allocator, &[(1, 10)]);
+    check_allocator(allocator, [(1, 10)]);
 }
 
 #[test]
 fn allocate_adds_value_for_two_ranges_starting_with_one() {
-    let mut allocator = create_allocator(&[(1, 5), (10, 15)]);
+    let mut allocator = create_allocator([(1, 5), (10, 15)]);
     assert_eq!(allocator.allocate(), 6);
-    check_allocator(allocator, &[(1, 6), (10, 15)]);
+    check_allocator(allocator, [(1, 6), (10, 15)]);
 }
 
 #[test]
 fn allocate_combines_two_adjacent_ranges_starting_with_one() {
-    let mut allocator = create_allocator(&[(1, 5), (7, 15)]);
+    let mut allocator = create_allocator([(1, 5), (7, 15)]);
     assert_eq!(allocator.allocate(), 6);
-    check_allocator(allocator, &[(1, 15)]);
+    check_allocator(allocator, [(1, 15)]);
 }
 
 #[test]
 fn allocate_combines_two_adjacent_ranges_starting_with_one_extra() {
-    let mut allocator = create_allocator(&[(1, 5), (7, 15), (20, 30)]);
+    let mut allocator = create_allocator([(1, 5), (7, 15), (20, 30)]);
     assert_eq!(allocator.allocate(), 6);
-    check_allocator(allocator, &[(1, 15), (20, 30)]);
+    check_allocator(allocator, [(1, 15), (20, 30)]);
 }
 
 #[test]
 fn allocate_adds_value_for_range_starting_with_two() {
-    let mut allocator = create_allocator(&[(2, 10)]);
+    let mut allocator = create_allocator([(2, 10)]);
     assert_eq!(allocator.allocate(), 1);
-    check_allocator(allocator, &[(1, 10)]);
+    check_allocator(allocator, [(1, 10)]);
 }
 
 #[test]
 fn allocate_adds_value_for_range_starting_with_two_extra() {
-    let mut allocator = create_allocator(&[(2, 10), (20, 30)]);
+    let mut allocator = create_allocator([(2, 10), (20, 30)]);
     assert_eq!(allocator.allocate(), 1);
-    check_allocator(allocator, &[(1, 10), (20, 30)]);
+    check_allocator(allocator, [(1, 10), (20, 30)]);
 }
 
 #[test]
 fn allocate_adds_value_for_range_starting_with_ten() {
-    let mut allocator = create_allocator(&[(10, 20)]);
+    let mut allocator = create_allocator([(10, 20)]);
     assert_eq!(allocator.allocate(), 1);
-    check_allocator(allocator, &[(1, 1), (10, 20)]);
+    check_allocator(allocator, [(1, 1), (10, 20)]);
 }