Data commit

Task/Power-set/Rust/power-set.rust

@@ -0,0 +1,29 @@
+use std::collections::BTreeSet;
+
+fn powerset<T: Ord + Clone>(mut set: BTreeSet<T>) -> BTreeSet<BTreeSet<T>> {
+    if set.is_empty() {
+        let mut powerset = BTreeSet::new();
+        powerset.insert(set);
+        return powerset;
+    }
+    // Access the first value. This could be replaced with `set.pop_first().unwrap()`
+    // But this is an unstable feature
+    let entry = set.iter().nth(0).unwrap().clone();
+    set.remove(&entry);
+    let mut powerset = powerset(set);
+    for mut set in powerset.clone().into_iter() {
+        set.insert(entry.clone());
+        powerset.insert(set);
+    }
+    powerset
+}
+
+fn main() {
+    let set = (1..5).collect();
+    let set = powerset(set);
+    println!("{:?}", set);
+
+    let set = ["a", "b", "c", "d"].iter().collect();
+    let set = powerset(set);
+    println!("{:?}", set);
+}