diff --git a/leetcode/1.rs b/leetcode/1.rs
new file mode 100644
index 0000000..b278370
--- /dev/null
+++ b/leetcode/1.rs
@@ -0,0 +1,30 @@
+use std::collections::HashMap;
+
+impl Solution {
+    /// This function takes a vector of integers (`nums`) and an integer (`target`) as input.
+    /// It returns a vector of integers.
+    ///
+    /// # Arguments
+    ///
+    /// * `nums` - A vector of integers.
+    /// * `target` - An integer that represents the target sum.
+    ///
+    /// # Returns
+    ///
+    /// This function returns a vector of integers.
+    pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
+        let mut map = HashMap::new();
+
+        for (i, &num) in nums.iter_mut().enumerate() {
+            let complement = target - num;
+
+            if let Some(&index) = map.get(&complement) {
+                return vec![index as i32, i as i32];
+            }
+
+            map.insert(num, i);
+        }
+
+        vec![]
+    }
+}