diff --git a/exercises/19_smart_pointers/arc1.rs b/exercises/19_smart_pointers/arc1.rs
index 3526ddcb..e581d851 100644
--- a/exercises/19_smart_pointers/arc1.rs
+++ b/exercises/19_smart_pointers/arc1.rs
@@ -21,19 +21,18 @@
 //
 // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #![forbid(unused_imports)] // Do not change this, (or the next) line.
 use std::sync::Arc;
 use std::thread;
 
 fn main() {
     let numbers: Vec<_> = (0..100u32).collect();
-    let shared_numbers = // TODO
+    let shared_numbers = Arc::new(numbers);
+    // numbers.iter().sum();
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
-        let child_numbers = // TODO
+        let child_numbers = Arc::clone(&shared_numbers);
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);
diff --git a/exercises/19_smart_pointers/cow1.rs b/exercises/19_smart_pointers/cow1.rs
index fcd3e0bb..3cbdcf73 100644
--- a/exercises/19_smart_pointers/cow1.rs
+++ b/exercises/19_smart_pointers/cow1.rs
@@ -48,7 +48,8 @@ mod tests {
         let slice = [0, 1, 2];
         let mut input = Cow::from(&slice[..]);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Borrowed(_) => Ok(()),
+            Cow::Owned(_) => Err("Expect"),
         }
     }
 
@@ -60,7 +61,8 @@ mod tests {
         let slice = vec![0, 1, 2];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            Cow::Borrowed(_) => Err("Expected owned value"),
         }
     }
 
@@ -72,7 +74,8 @@ mod tests {
         let slice = vec![-1, 0, 1];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            Cow::Borrowed(_) => Err(""),
         }
     }
 }