A few problems

two-sum/sol.rs

@@ -0,0 +1,16 @@
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
+        let mut done: HashMap<i32, i32> = HashMap::new();
+        nums
+            .into_iter()
+            .enumerate()
+            .find_map(|(i2, n2)|
+                done.get(&n2)
+                    .and_then(|i1| Some(vec![*i1, i2 as i32]))
+                    .or_else(|| done.insert(target-n2, i2 as i32).and(None))
+            )
+            .unwrap()
+    }
+}