diff --git a/leetcode/1 - twosum/two_sum.swift b/leetcode/1 - twosum/two_sum.swift
new file mode 100644
index 0000000..2ce8c85
--- /dev/null
+++ b/leetcode/1 - twosum/two_sum.swift	
@@ -0,0 +1,19 @@
+import Cocoa
+
+class Solution {
+    func twoSum(_ nums: [Int], _ target: Int) -> [Int] {
+       var seen: Set<Int> = []
+    
+    for i in 0 ... nums.count - 1 {
+        let complement = target - nums[i]
+        if seen.contains(complement) {
+            if let complementIndex = nums.firstIndex(of: complement) {
+                return([complementIndex,i])
+            }
+        } else {
+            seen.insert(nums[i])
+        }
+    }
+    return []
+    }
+}