[rust] Sublist

1 files changed, 19 insertions, 0 deletions

diff --git a/rust/sublist/src/lib.rs b/rust/sublist/src/lib.rs
new file mode 100644
index 0000000..cc62362
--- /dev/null
+++ b/rust/sublist/src/lib.rs
@@ -0,0 +1,19 @@
+#[derive(Debug, PartialEq, Eq)]
+pub enum Comparison {
+    Equal,
+    Sublist,
+    Superlist,
+    Unequal,
+}
+
+pub fn sublist<T: PartialEq>(fst: &[T], snd: &[T]) -> Comparison {
+    match (fst.len(),snd.len()) {
+        (0,0) => Comparison::Equal,
+        (0,_) => Comparison::Sublist,
+        (_,0) => Comparison::Superlist,
+        (n,m) if n < m && snd.windows(n).any(|s| fst == s) => Comparison::Sublist,
+        (n,m) if n > m && fst.windows(m).any(|f| snd == f) => Comparison::Superlist,
+        _ if fst == snd => Comparison::Equal,
+        _ => Comparison::Unequal
+    }
+}