diff --git a/two-sum/nakjun12.ts b/two-sum/nakjun12.ts
new file mode 100644
index 000000000..8c1ac2570
--- /dev/null
+++ b/two-sum/nakjun12.ts
@@ -0,0 +1,20 @@
+/*
+ * TC: O(n)
+ * SC: O(n)
+ * */
+function twoSum(nums: number[], target: number): number[] {
+  const indices = {};
+
+  for (let i = 0; i < nums.length; i++) {
+    const curNum = nums[i];
+    const complement = target - curNum;
+
+    if (complement in indices) {
+      return [indices[complement], i];
+    }
+
+    indices[curNum] = i;
+  }
+
+  return [];
+}